Average Weather in Suwanee Georgia, United States
In Suwanee, the summers are hot and muggy; the winters are short, cold, and wet; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 35°F to 89°F and is rarely below 23°F or above 95°F.
Based on the tourism score, the best times of year to visit Suwanee for warm-weather activities are from early May to mid June and from late August to mid October.
The hot season lasts for 3.8 months, from May 24 to September 17, with an average daily high temperature above 81°F. The hottest day of the year is July 22, with an average high of 89°F and low of 71°F.
The cool season lasts for 2.9 months, from November 29 to February 25, with an average daily high temperature below 59°F. The coldest day of the year is January 23, with an average low of 35°F and high of 52°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 Suwanee, 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 Suwanee begins around July 20 and lasts for 4.1 months, ending around November 23. On October 8, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 67% of the time, and overcast or mostly cloudy 33% of the time.
The cloudier part of the year begins around November 23 and lasts for 7.9 months, ending around July 20. On January 4, the cloudiest day of the year, the sky is overcast or mostly cloudy 54% of the time, and clear, mostly clear, or partly cloudy 46% 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 Suwanee varies throughout the year.
The wetter season lasts 3.9 months, from May 2 to August 30, with a greater than 32% chance of a given day being a wet day. The chance of a wet day peaks at 43% on July 9.
The drier season lasts 8.1 months, from August 30 to May 2. The smallest chance of a wet day is 20% on October 16.
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 43% on July 9.
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. Suwanee experiences some seasonal variation in monthly rainfall.
Rain falls throughout the year in Suwanee. The most rain falls during the 31 days centered around March 1, with an average total accumulation of 4.6 inches.
The least rain falls around October 24, with an average total accumulation of 3.1 inches.
Average Monthly Rainfall
The sliding 31-day liquid-equivalent quantity of snowfall in Suwanee does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Suwanee varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 53 minutes of daylight; the longest day is June 21, with 14 hours, 26 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 6:24 AM on June 13, and the latest sunrise is 1 hour, 33 minutes later at 7:57 AM on November 3. The earliest sunset is at 5:26 PM on December 5, and the latest sunset is 3 hours, 25 minutes later at 8:51 PM on June 29.
Daylight saving time (DST) is observed in Suwanee during 2018, starting in the spring on March 11, lasting 7.8 months, and ending in the fall on November 4.
Sunrise & Sunset with Twilight and Daylight Saving Time
Suwanee experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 4.2 months, from May 22 to September 29, during which time the comfort level is muggy, oppressive, or miserable at least 21% of the time. The muggiest day of the year is July 25, with muggy conditions 84% of the time.
The least muggy day of the year is February 28, when muggy conditions are essentially unheard of.
Humidity Comfort Levels
The average hourly wind speed in Suwanee experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 6.8 months, from October 20 to May 13, with average wind speeds of more than 5.0 miles per hour. The windiest day of the year is March 8, with an average hourly wind speed of 6.3 miles per hour.
The calmer time of year lasts for 5.2 months, from May 13 to October 20. The calmest day of the year is August 5, with an average hourly wind speed of 3.8 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Suwanee varies throughout the year.
The wind is most often from the east for 3.6 months, from August 11 to November 30, with a peak percentage of 46% on September 8. The wind is most often from the west for 8.4 months, from November 30 to August 11, with a peak percentage of 36% on January 1.
Best Time of Year to Visit
To characterize how pleasant the weather is in Suwanee throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best times of year to visit Suwanee for general outdoor tourist activities are from early May to mid June and from late August to mid October, with a peak score in the third week of September.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Suwanee for hot-weather activities is from mid June to mid September, with a peak score in the second week of August.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
The growing season in Suwanee typically lasts for 8.0 months (245 days), from around March 18 to around November 18, rarely starting before February 21 or after April 8, and rarely ending before October 31 or after December 8.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in Suwanee should appear around February 15, only rarely appearing before January 29 or after March 4.
Growing Degree Days
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 4.5 months, from April 12 to August 29, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest day of the year is June 6, with an average of 6.8 kWh.
The darker period of the year lasts for 2.8 months, from November 13 to February 5, with an average daily incident shortwave energy per square meter below 3.4 kWh. The darkest day of the year is December 23, with an average of 2.5 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Suwanee are 34.051 deg latitude, -84.071 deg longitude, and 1,010 ft elevation.
The topography within 2 miles of Suwanee contains only modest variations in elevation, with a maximum elevation change of 246 feet and an average elevation above sea level of 1,001 feet. Within 10 miles contains only modest variations in elevation (758 feet). Within 50 miles contains significant variations in elevation (3,976 feet).
The area within 2 miles of Suwanee is covered by artificial surfaces (94%), within 10 miles by artificial surfaces (82%) and trees (11%), and within 50 miles by trees (59%) and artificial surfaces (25%).
This report illustrates the typical weather in Suwanee, 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Suwanee.
For each station, the records are corrected for the elevation difference between that station and Suwanee 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 Suwanee is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Suwanee and a given station.
The stations contributing to this reconstruction are: Dekalb-Peachtree Airport (33%, 29 kilometers, southwest); Lee Gilmer Memorial Airport (26%, 33 kilometers, northeast); Barrow County Airport (22%, 38 kilometers, east); and Cherokee County Airport (19%, 42 kilometers, northwest).
Time zones for aiports and weather stations are provided by AskGeo.com .