Average Weather in St. Petersburg Florida, United States
In St. Petersburg, the summers are long, hot, oppressive, wet, and mostly cloudy and the winters are short, cool, windy, and partly cloudy. Over the course of the year, the temperature typically varies from 56°F to 89°F and is rarely below 46°F or above 93°F.
The hot season lasts for 4.6 months, from May 18 to October 5, with an average daily high temperature above 85°F. The hottest day of the year is July 23, with an average high of 89°F and low of 79°F.
The cool season lasts for 2.8 months, from December 6 to March 1, with an average daily high temperature below 73°F. The coldest day of the year is January 18, with an average low of 56°F and high of 69°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
In St. Petersburg, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in St. Petersburg begins around October 2 and lasts for 8.2 months, ending around June 8. On May 1, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 65% of the time, and overcast or mostly cloudy 35% of the time.
The cloudier part of the year begins around June 8 and lasts for 3.8 months, ending around October 2. On July 10, the cloudiest day of the year, the sky is overcast or mostly cloudy 68% of the time, and clear, mostly clear, or partly cloudy 32% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in St. Petersburg varies very significantly throughout the year.
The wetter season lasts 3.6 months, from June 6 to September 23, with a greater than 43% chance of a given day being a wet day. The chance of a wet day peaks at 70% on July 31.
The drier season lasts 8.4 months, from September 23 to June 6. The smallest chance of a wet day is 14% on November 25.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 70% on July 31.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. St. Petersburg experiences extreme seasonal variation in monthly rainfall.
Rain falls throughout the year in St. Petersburg. The most rain falls during the 31 days centered around August 16, with an average total accumulation of 6.4 inches.
The least rain falls around November 11, with an average total accumulation of 1.7 inches.
Average Monthly Rainfall
The length of the day in St. Petersburg varies over the course of the year. In 2017, the shortest day is December 21, with 10 hours, 23 minutes of daylight; the longest day is June 21, with 13 hours, 54 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 6:34 AM on June 9, and the latest sunrise is 1 hour, 10 minutes later at 7:43 AM on November 4. The earliest sunset is at 5:35 PM on November 30, and the latest sunset is 2 hours, 56 minutes later at 8:30 PM on July 1.
Daylight saving time (DST) is observed in St. Petersburg during 2017, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.
Sunrise & Sunset with Twilight and Daylight Saving Time
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
St. Petersburg experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 8.0 months, from March 31 to November 29, during which time the comfort level is muggy, oppressive, or miserable at least 36% of the time. The muggiest day of the year is August 1, with muggy conditions 100% of the time.
The least muggy day of the year is January 30, with muggy conditions 14% of the time.
Humidity Comfort Levels
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in St. Petersburg experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 7.8 months, from September 17 to May 12, with average wind speeds of more than 4.6 miles per hour. The windiest day of the year is November 7, with an average hourly wind speed of 5.8 miles per hour.
The calmer time of year lasts for 4.2 months, from May 12 to September 17. The calmest day of the year is July 20, with an average hourly wind speed of 3.5 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in St. Petersburg varies throughout the year.
The wind is most often from the east for 2.7 months, from March 17 to June 8 and for 2.7 months, from August 10 to November 2, with a peak percentage of 52% on September 24. The wind is most often from the west for 2.1 months, from June 8 to August 10, with a peak percentage of 36% on July 6. The wind is most often from the north for 4.5 months, from November 2 to March 17, with a peak percentage of 38% on January 1.
St. Petersburg is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average water temperature experiences significant seasonal variation over the course of the year.
The time of year with warmer water lasts for 4.1 months, from June 7 to October 9, with an average temperature above 81°F. The day of the year with the warmest water is August 10, with an average temperature of 86°F.
The time of year with cooler water lasts for 3.3 months, from December 19 to March 27, with an average temperature below 69°F. The day of the year with the coolest water is February 5, with an average temperature of 65°F.
Average Water Temperature
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy experiences significant seasonal variation over the course of the year.
The brighter period of the year lasts for 2.0 months, from April 2 to June 2, with an average daily incident shortwave energy per square meter above 6.1 kWh. The brightest day of the year is May 1, with an average of 6.8 kWh.
The darker period of the year lasts for 2.6 months, from November 11 to January 30, with an average daily incident shortwave energy per square meter below 4.2 kWh. The darkest day of the year is December 21, with an average of 3.5 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of St. Petersburg are 27.771 deg latitude, -82.679 deg longitude, and 33 ft elevation.
The topography within 2 miles of St. Petersburg is essentially flat, with a maximum elevation change of 49 feet and an average elevation above sea level of 39 feet. Within 10 miles is also essentially flat (62 feet). Within 50 miles is essentially flat (259 feet).
The area within 2 miles of St. Petersburg is covered by artificial surfaces (100%), within 10 miles by water (57%) and artificial surfaces (38%), and within 50 miles by water (54%) and artificial surfaces (20%).
This report illustrates the typical weather in St. Petersburg, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 2 weather stations near enough to contribute to our estimation of the temperature and dew point in St. Petersburg.
For each station, the records are corrected for the elevation difference between that station and St. Petersburg according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at St. Petersburg is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between St. Petersburg and a given station.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.