Climate of the Tampa Bay area

Main articles: Tampa, Florida; St. Petersburg, Florida; and Tampa Bay area

The Tampa Bay area has a humid subtropical climate (Köppen Cfa), closely bordering a tropical climate near the waterfront areas. There are two basic seasons in the Tampa Bay area, a hot and wet season from May through October, and a mild and dry season from November through April.

Landsat 8 image of Tampa Bay Region

Nearly two-thirds of the annual precipitation falls in the months of June through September. The area is listed by the United States Department of Agriculture (USDA) as being in hardiness zone 10a as well as hardiness zone 10b along the immediate coast and in peninsular Pinellas;^[1] which is about the northern limit of where coconut palms and royal palms can be grown. Highs usually range between 65 and 95 °F (18–35 °C) year round. Tampa's official high has never reached 100 °F (38 °C) – the city's all-time record temperature is 99 °F (37 °C). St. Petersburg's all-time record high is exactly 100 °F (38 °C).^[2]

Pinellas County lies on a peninsula between Tampa Bay and the Gulf of Mexico, and much of the city of Tampa lies on a smaller peninsula jutting out into Tampa Bay. This proximity to large bodies of water both moderates temperatures and introduces large amounts of humidity into the atmosphere. In general, the local communities farthest from the coast have larger temperature ranges, both during a single day and throughout the seasons of the year.^[3]

Seasonal weather

Tampa
Climate chart (explanation)
J F M A M J J A S O N D     2.7     71 53     2.6     74 56     2.5     78 59     2.6     83 65     2.6     88 70     7.4     91 75     7.8     91 77     9     91 77     6.1     90 75     2.3     86 69     1.4     79 61     2.6     74 56 █ Average max. and min. temperatures in °F █ Precipitation totals in inches Source:NOAA 1991-2020 Climate Normals^[4]
Metric conversion J F M A M J J A S O N D     67     22 12     67     23 13     64     25 15     65     28 18     66     31 21     187     33 24     197     33 25     229     33 25     155     32 24     59     30 21     36     26 16     65     23 13 █ Average max. and min. temperatures in °C █ Precipitation totals in mm

Wet season

 

Cumulus clouds building over the Tampa Convention Center on a summer afternoon

The warm and rainy season typically begins in late May and runs through October.^[5] Average high temperatures are in the low 90s °F (around 32 °C) with lows in the mid-70s °F (around 24 °C) during this period, and the combination of warm temperatures and high humidity brings an almost daily chance of rain and thunderstorms, especially in the afternoon. Day-to-day weather is remarkably consistent, with summertime average highs and lows within five to ten degrees of the record high and low for any given date.^[6]

In the typical summertime weather pattern, the combination of daytime heating and the interaction of the Gulf and Atlantic sea breezes creates thermal-fueled cumulus clouds over the Florida peninsula. These can produce rain showers or grow into towering thunderheads, either of which tend to drift westward on upper-level winds produced by the Bermuda high, a semi-permanent weather feature over the Atlantic Ocean that strengthens during the summer months.^[5] These storms can form anywhere across Central Florida from the interior near Orlando to along the west coast, depending on the wind and local weather conditions. Wherever they develop, Tampa's most common summer weather pattern results in afternoon thundershowers that usually rain themselves out by sunset, though on occasion, a storm cell will persist and drift west to the Gulf of Mexico to produce nighttime lightning displays visible from local beaches.^[3]

A less common summer weather pattern is for prevailing westerly winds to cause overnight thundershowers to form offshore along a land breeze front. These storms bring morning rain to the Tampa area before moving inland later in the day, reversing the more typical timing. While afternoon storms are usually followed by a clear and cooler evening, morning rain often results in higher than usual humidity levels and the possibility of more storms developing in the afternoon.^[5]

Summer storms typically bring brief periods of heavy rain and gusty winds with frequent cloud-to-ground lightning. They can grow severe, bringing strong straight-line winds, small hail, and torrential rain, and an occasional tornado. (While Florida sees the highest number of tornadoes per square mile of any state, the majority are small, weak, and short-lived compared to those seen in mid-western states.^[7]) Waterspouts sometimes form when outflows from adjacent storm cells interact and begin to rotate over water, creating a funnel cloud over Tampa Bay or off the gulf beaches. These features usually stay offshore but occasionally reach land as a short-lived weak tornado.^[8]

The Tampa Bay area is sometimes referred to as the "Lightning Capital of the World" for its frequent thunderstorms.^[9] Though Central Florida receives as much lightning during the summer months as the world's true lightning leaders such as the Lake Victoria region of Africa and the central Amazon River Basin, thunderstorms are much less common from about October to May, so the area from Tampa to Orlando is more accurately deemed the "Lightning Capital of North America".^[3][10] An average of about a dozen people are killed by lightning in Florida every year, with several annually in the Tampa area.,^[11] and TECO Energy, Tampa's primary electric utility, spends several millions dollars annually to repair transformers and other equipment damaged by lightning strikes.^[12] University of Florida lightning expert Martin A. Uman has calculated that the average resident is within a half-mile of 10 to 15 lightning strikes every year.^[13]

Dry season

 

Coconut palms at the Gizella Kopsick Palm Arboretum in northeast St. Petersburg.

The dry season often begins in early November and can last into early May. The local weather during these months is normally sunny, mild, and quite dry, with a general cooling trend through the fall and a slow increase in temperatures starting in February. Highs during the coolest part of the winter average around 70 °F (21 °C), usually with sunny skies. The occasional passage of a cold front will bring rain followed by a few days of cooler temperatures.^[3] Lows rarely reach freezing 32 °F (0 °C), an occurrence which happens, on average, once every other year in areas away from the water and less frequently in areas on Tampa Bay or the Gulf of Mexico.^[3] While deep freezes are very infrequent, serious cold snaps are a significant concern due to the diverse range of freeze-sensitive agriculture and aquaculture industries in the area as well as tropical landscaping such as coconut palms and royal palms.

Frozen precipitation is very rare in the Tampa Bay area. The only known measurable snowfall in Tampa after 1900 occurred on January 19, 1977. While the accumulation amounted to less than 0.5 inches (13 mm), the city is so unaccustomed to snow that public schools closed for the day and many businesses and roadways closed until it melted away that afternoon.^[14] Many residents of southern Pinellas County reported a light snowfall on December 23, 1989. However, no snow fell at official weather stations, and the weather record indicates that light sleet fell on St. Petersburg that day.^[15]

The winter of 2009–2010 was one of the coldest in local history. Both Tampa and St. Petersburg set records for consecutive days in which the high temperature did not reach 60 °F (16 °C), and Tampa experienced ten consecutive days with a low temperature below freezing.^[16][17] Much of the area received a "wintry mix" of rain and sleet on January 9–10.^[18]

According to The Weather Channel, Tampa's all-time record low temperature is 18 °F (−8 °C) and St. Petersburg's is 20 °F (−7 °C), both occurring during the same cold snap on December 13, 1962.^[19]

During El Niño, the Tampa Bay area receives cooler and wetter conditions during the dry season while during La Niña, the Tampa Bay area becomes drier and warmer than normal.

Precipitation and sunshine trends

Due to the frequent summer thunderstorms, Tampa has a pronounced wet season, receiving a yearly average of about 30 inches (760 mm) of rain from June to September but only about 19 inches (480 mm) during the remaining eight months of the year combined. The historical averages late in the wet season are augmented by the passage of tropical cyclones, which can drop several inches of rain in just a few hours. Outside of the summer rainy season, most of the area's precipitation is delivered by occasional weather fronts - cold fronts often bring brief but intense rain while warm fronts tend to bring light rain over longer periods of time.^[12]

Precipitation and temperature averages for the city of Tampa itself tend to fall near the median for the area. Communities to the interior tend to receive a bit more rain and experience slightly wider temperature fluctuations, while those on the Gulf coast tend to receive a bit less rain and less pronounced temperature differences, both in a single day and through the year.^[20]

The area receives plentiful sunshine throughout the year, averaging a total of 2920 hours, or 66.7% of the possible total.^[21] The daily sunshine amount is highest in May, when the sun's angle of incidence brings more hours of daylight but the rainy season has not yet begun.^[21]

Tropical systems

 

Hurricane Frances over Florida in 2004

June through November is hurricane season in the Atlantic Basin and Caribbean Sea, with the most tropical activity occurring between mid-August to mid-October.^[22] Rain dropped by tropical systems is an important component of the area's annual precipitation and is vital for replenishing the water supply of communities around Tampa Bay.^[23]

The area is threatened by tropical systems almost every year and feels some effect from passing storms several times per decade. However, due to Tampa Bay's location on the west coast and the typical steering winds for storms, landfall in the area is very uncommon, with estimates of the probability of a hurricane making landfall in the Tampa Bay area during any given year ranging from 1 in 25 to 1 in 50.^[12][24] The small village of Tampa was devastated by the Great Gale of 1848, and the area suffered major damage during the Tampa Bay Hurricane of 1921. Since then, however, Tampa Bay has not seen the landfall of any hurricane. Manatee County, which is technically not part of the Tampa Bay area, in 1946 was the site of a Category 1 hurricane that lost hurricane strength immediately after landfall.^[25][26][27]

The 2004 Atlantic Hurricane Season was historically busy for the Tampa Bay area. The region was affected by a record four hurricanes that year; Frances, Jeanne, Charley, and to a lesser extent, Ivan.^[28] Jeanne and Frances passed over Tampa as tropical storms after making their way across the state from the east coast.^[29][30] Charley was forecast to make a direct hit on Tampa Bay from the south-southwest, which would have been the worst-case scenario for local storm surge flooding.^[31] But the storm made a sudden and unexpected turn to the northeast and brought only tropical storm force winds to the region, devastating the Ft. Myers/Port Charlotte area instead.^[32][33] Ivan also threatened the area as it moved north up the eastern Gulf of Mexico. It remained far to the west of central Florida, however, and brought only a bit of rain and wind to Tampa Bay before eventually slamming into coastal Alabama and the Florida Panhandle.^[34]

On September 10, 2017, Hurricane Irma struck the Florida Keys and made landfall near Marco Island in southwest Florida as a Category 3 storm. Irma moved north up the length of the Florida peninsula and had weakened to a Category 1 storm by the time it neared central Florida. On the night of September 10 and 11, the eye passed east of Tampa through eastern Hillsborough County, bringing at least tropical storm winds to the entire Tampa Bay area. Irma caused significant damage to the region, particularly to the electrical grid.

Tampa data

Climate data for Tampa, Florida (Tampa Int'l), 1991−2020 normals,^[a] extremes 1890−present^[b]
Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Record high °F (°C)	86 (30)	89 (32)	92 (33)	96 (36)	98 (37)	99 (37)	98 (37)	98 (37)	96 (36)	95 (35)	92 (33)	86 (30)	99 (37)
Mean maximum °F (°C)	81.8 (27.7)	82.5 (28.1)	85.4 (29.7)	89.0 (31.7)	93.4 (34.1)	95.0 (35.0)	94.8 (34.9)	94.8 (34.9)	93.8 (34.3)	91.1 (32.8)	86.4 (30.2)	82.5 (28.1)	96.2 (35.7)
Mean daily maximum °F (°C)	71.3 (21.8)	74.0 (23.3)	77.8 (25.4)	83.0 (28.3)	88.3 (31.3)	90.5 (32.5)	91.0 (32.8)	91.2 (32.9)	90.2 (32.3)	85.6 (29.8)	78.9 (26.1)	73.9 (23.3)	83.0 (28.3)
Daily mean °F (°C)	62.0 (16.7)	64.7 (18.2)	68.6 (20.3)	73.9 (23.3)	79.5 (26.4)	82.9 (28.3)	83.8 (28.8)	84.0 (28.9)	82.7 (28.2)	77.4 (25.2)	69.8 (21.0)	64.9 (18.3)	74.5 (23.6)
Mean daily minimum °F (°C)	52.8 (11.6)	55.5 (13.1)	59.3 (15.2)	64.8 (18.2)	70.6 (21.4)	75.4 (24.1)	76.6 (24.8)	76.8 (24.9)	75.3 (24.1)	69.2 (20.7)	60.7 (15.9)	55.9 (13.3)	66.1 (18.9)
Mean minimum °F (°C)	34.4 (1.3)	38.8 (3.8)	43.4 (6.3)	51.6 (10.9)	61.2 (16.2)	69.9 (21.1)	71.8 (22.1)	72.5 (22.5)	69.2 (20.7)	54.9 (12.7)	45.3 (7.4)	39.5 (4.2)	32.8 (0.4)
Record low °F (°C)	21 (−6)	22 (−6)	29 (−2)	38 (3)	49 (9)	53 (12)	63 (17)	66 (19)	54 (12)	40 (4)	23 (−5)	18 (−8)	18 (−8)
Average precipitation inches (mm)	2.65 (67)	2.62 (67)	2.52 (64)	2.55 (65)	2.60 (66)	7.37 (187)	7.75 (197)	9.03 (229)	6.09 (155)	2.34 (59)	1.40 (36)	2.56 (65)	49.48 (1,257)
Average precipitation days (≥ 0.01 in)	7.1	6.6	5.9	5.7	6.2	13.3	16.6	16.2	12.8	7.2	4.6	6.0	108.2
Average relative humidity (%)	74.9	73.0	71.8	69.0	69.8	74.4	76.6	78.4	77.6	74.2	75.0	75.0	74.1
Average dew point °F (°C)	50.2 (10.1)	50.7 (10.4)	55.6 (13.1)	59.2 (15.1)	64.9 (18.3)	70.9 (21.6)	72.7 (22.6)	73.0 (22.8)	71.2 (21.8)	64.2 (17.9)	57.7 (14.3)	52.3 (11.3)	61.9 (16.6)
Mean monthly sunshine hours	213.9	231.7	260.4	279.0	337.9	321.0	334.8	294.5	267.0	235.6	195.0	195.3	3,166.1
Mean daily sunshine hours	6.9	8.2	8.4	9.3	10.9	10.7	10.8	9.5	8.9	7.6	6.5	6.3	8.7
Mean daily daylight hours	10.6	11.2	12.0	12.9	13.5	13.9	13.7	13.1	12.3	11.5	10.8	10.4	12.2
Percent possible sunshine	65	73	70	72	81	77	79	73	72	66	60	61	71
Average ultraviolet index	4.4	6.1	8.0	9.6	10.1	10.4	10.5	10.1	8.7	6.7	4.8	4.0	7.7
Source 1: NOAA (relative humidity, dew point and sun 1961−1990)^[35]^[36]^[37] Weather Channel^[38]
Source 2: UV Index Today (1995 to 2022)^[39] Source 3: Weather Atlas (sunshine data) ^[40]

See or edit raw graph data.

See also

• Climate of Florida

Notes

1. Mean monthly maxima and minima (i.e. the highest and lowest temperature readings during an entire month or year) calculated based on data at said location from 1991 to 2020.
2. Official records for Tampa were kept at downtown from April 1890 to December 1940, Peter O. Knight Airport from January 1941 to 5 June 1946, and at Tampa Int'l since 7 June 1946. For more information, see ThreadEx

References

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3. Winsberg, Morton (2003). Florida Weather. Gainesville: University Press of Florida. ISBN 978-0-8130-2684-8.
4. "Tampa 1991-2020 Monthly Climate Normals". www.weather.gov. NOAA.
5. Mulligan, Michaela (August 21, 2023). "Tampa Bay's afternoon storms are a summer staple. Why is this year different?". Tampa Bay Times.
6. "National Weather Service - Tampa climate data". National Oceanic and Atmospheric Administration (NOAA). Retrieved 2017-07-01.
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8. "Waterspout forms in St. Pete Beach". WTSP-TV. June 27, 2022.
9. Jeff Klinkenberg (2008). Meet Thunderman. 2012-03-15 at the Wayback Machine St. Petersburg Times. Retrieved on 2009-02-06.
10. "Area just outside of Orlando named lightning capital of the U.S." WFLA-TV. January 7, 2023.
11. St. Petersburg Times (1999). Lightning capital of the nation. 2011-04-12 at the Wayback Machine Retrieved on 2009-02-06.
12. Henry, James (1998). The Climate and Weather of Florida. Sarasota, Florida: Pineapple Press (FL). ISBN 978-1-56164-036-2.
13. Lightning Research Laboratory (UF) 2013-12-19 at the Wayback Machine. Lightning.ece.ufl.edu. Retrieved on 2009-02-06.
14. ShannonMulaire (2009-01-28). . Myfoxtampabay.com. Archived from the original on 2012-02-25. Retrieved 2010-06-21.
15. The Great Tampa Bay snow of '89. St. Petersburg Times. Retrieved on 2009-02-17.
16. . .tbo.com. 2010-03-19. Archived from the original on 2010-03-29. Retrieved 2010-06-21.
17. "Record Breaking 10 Straight Days Below 60 Degrees WTSP.com 10 Connects". Wtsp.com. Archived from the original on 2013-02-09. Retrieved 2010-06-21.
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20. "The Weather Channel (weather.com)". The Weather Channel Interactive, Inc. Retrieved 2006-11-25.
21. Climatological Information for Almaty, Kazakhstan 2016-03-04 at the Wayback Machine. Retrieved 16 August 2012.
22. National Weather Service Office in Tampa Bay, Florida (2009). Tampa Bay Area Tropical Weather Page. National Weather Service Southern Region Headquarters. Retrieved on 2009-02-06.
23. Craig Pittman (2009). Tampa Bay Water likely to overdraw from aquifer this spring. 2012-03-15 at the Wayback Machine St. Petersburg Times. Retrieved on 2009-02-06.
24. Bob Macpherson (2008). Experts brief citizens on hurricane preparedness. Tampa Bay Beach Beacon. Retrieved on 2009-02-17.
25. Chris Landsea (2005). Subject: E24) How long has it been since a hurricane or a major hurricane hit a given community in the United States? Hurricane Research Division. Retrieved on 2009-02-06.
26. McClure, Brian (May 21, 2010). . Tampa Bay Times. Archived from the original on October 25, 2016. Retrieved October 24, 2016.
27. Barnes, Jay (2012). Florida's Hurricane History. University of North Carolina Press. p. 169. ISBN 978-1-4696-0021-5.
28. Jamie Thompson and Chase Squires (2004). 2004 Hurricane Season Ends. St. Petersburg Times. Retrieved on 2009-02-17.
29. Miles B. Lawrence and Hugh D. Cobb (2005). Tropical Cyclone Report: Hurricane Jeanne 13–28 September 2004. National Hurricane Center. Retrieved on 2009-02-17.
30. John L. Beven II (2004). Tropical Cyclone Report: Hurricane Frances 25 August – 8 September 2004. National Hurricane Center. Retrieved on 2009-02-17.
31. Weather: Shrinking core reduced storm surge
32. State: Countdown to landfall
33. Richard J. Pasch, Daniel P. Brown, and Eric S. Blake (2005). Tropical Cyclone Report: Hurricane Charley 9–14 August 2004. National Hurricane Center. Retrieved on 2009-02-17.
34. Stacey R. Stewart (2005). Tropical Cyclone Report: Hurricane Ivan 2–24 September 2004. August 21, 2007, at the Wayback Machine National Hurricane Center. Retrieved on 2009-02-17.
35. "NOWData – NOAA Online Weather Data". National Oceanic and Atmospheric Administration. Retrieved May 23, 2021.
36. "Summary of Monthly Normals 1991–2020". National Oceanic and Atmospheric Administration. Retrieved May 23, 2021.
37. "WMO Climate Normals for TAMPA/INT'L ARPT FL 1961–1990". National Oceanic and Atmospheric Administration. Retrieved 2020-07-18.
38. "Average Weather for Tampa, FL - Temperature and Precipitation". The Weather Channel. Retrieved 2011-10-03.
39. "Historical UV Index Data - Tampa, FL". UV Index Today. Retrieved April 21, 2023.
40. "Tampa, Florida - Monthly weather forecast and Climate data". Weather Atlas. Retrieved 19 May 2023.