The National Weather Service forecasts sunny skies here in Cobb County on Friday, September 20, 2024, with a high near 89 degrees.
Tonight it is expected to be mostly clear, with an overnight low of around 66 degrees.
What you will read in this article
- The extended forecast for Cobb County
- Last month’s climate summary for the metro Atlanta region
- The climate almanac for metro Atlanta
- What the National Weather Service is, and what it does
What does the extended forecast have in store?
This forecast is centered on Dobbins Air Reserve Base in Marietta.
Today
Sunny, with a high near 89. Calm wind becoming north around 5 mph in the afternoon.
Tonight
Mostly clear, with a low around 66. Calm wind becoming southeast around 5 mph.
Saturday
Sunny, with a high near 90. East wind around 5 mph becoming west in the afternoon.
Saturday Night
Partly cloudy, with a low around 67. Calm wind.
Sunday
Sunny, with a high near 92. Calm wind becoming west around 5 mph in the afternoon.
Sunday Night
Mostly clear, with a low around 68.
Monday
Mostly sunny, with a high near 91.
Monday Night
Partly cloudy, with a low around 69.
Tuesday
Mostly sunny, with a high near 89.
Tuesday Night
A 20 percent chance of showers before 2 a.m. Partly cloudy, with a low around 67.
Wednesday
A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 85.
Wednesday Night
A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 63.
Thursday
A 20 percent chance of showers. Mostly sunny, with a high near 83.
What was the climate like in the latest reporting period?
The NWS climate summary for metro Atlanta has now been updated with August 2024 figures.
In an article entitled What is the Difference between Climate and Weather?, the National Ocean Service describes the difference as follows:
“Weather is what you see outside on any particular day. So, for example, it may be 75° degrees and sunny or it could be 20° degrees with heavy snow. That’s the weather.
“Climate is the average of that weather. For example, you can expect snow in the Northeast in January or for it to be hot and humid in the Southeast in July. This is climate. The climate record also includes extreme values such as record high temperatures or record amounts of rainfall. If you’ve ever heard your local weather person say “today we hit a record high for this day,” she is talking about climate records.
“So when we are talking about climate change, we are talking about changes in long-term averages of daily weather. In most places, weather can change from minute-to-minute, hour-to-hour, day-to-day, and season-to-season. Climate, however, is the average of weather over time and space.”
The climate report for the Atlanta area for the previous month shows how much departure from the average temperatures that month represents. The average temperature for a date is the average over a 30-year period.
| Date | Max | Min | Average | Departure from norm | Precipitation |
| 2024-08-01 | 94 | 74 | 84 | 2.8 | 0 |
| 2024-08-02 | 93 | 77 | 85 | 3.9 | 0.04 |
| 2024-08-03 | 91 | 74 | 82.5 | 1.4 | 0 |
| 2024-08-04 | 91 | 74 | 82.5 | 1.4 | T |
| 2024-08-05 | 92 | 75 | 83.5 | 2.5 | T |
| 2024-08-06 | 93 | 77 | 85 | 4 | 0 |
| 2024-08-07 | 96 | 74 | 85 | 4.1 | 0 |
| 2024-08-08 | 96 | 77 | 86.5 | 5.6 | 0 |
| 2024-08-09 | 95 | 76 | 85.5 | 4.7 | 0 |
| 2024-08-10 | 93 | 73 | 83 | 2.2 | 0 |
| 2024-08-11 | 92 | 69 | 80.5 | -0.2 | 0 |
| 2024-08-12 | 92 | 70 | 81 | 0.4 | 0 |
| 2024-08-13 | 93 | 71 | 82 | 1.4 | 0 |
| 2024-08-14 | 92 | 76 | 84 | 3.5 | 0 |
| 2024-08-15 | 90 | 74 | 82 | 1.6 | 0 |
| 2024-08-16 | 91 | 72 | 81.5 | 1.2 | 0.39 |
| 2024-08-17 | 95 | 71 | 83 | 2.8 | 0.11 |
| 2024-08-18 | 91 | 72 | 81.5 | 1.3 | 0.23 |
| 2024-08-19 | 89 | 70 | 79.5 | -0.6 | 0 |
| 2024-08-20 | 89 | 70 | 79.5 | -0.5 | 0 |
| 2024-08-21 | 85 | 67 | 76 | -3.8 | 0 |
| 2024-08-22 | 85 | 69 | 77 | -2.7 | 0 |
| 2024-08-23 | 85 | 65 | 75 | -4.6 | 0 |
| 2024-08-24 | 88 | 66 | 77 | -2.5 | 0 |
| 2024-08-25 | 90 | 69 | 79.5 | 0.1 | 0 |
| 2024-08-26 | 92 | 70 | 81 | 1.8 | 0 |
| 2024-08-27 | 94 | 71 | 82.5 | 3.4 | 0 |
| 2024-08-28 | 97 | 74 | 85.5 | 6.5 | 0 |
| 2024-08-29 | 98 | 76 | 87 | 8.2 | 0 |
| 2024-08-30 | 96 | 75 | 85.5 | 6.8 | 0.03 |
| 2024-08-31 | M | M | M | M | M |
Climate Almanac for metro Atlanta
This almanac provides information on past climate conditions for September 20, allowing comparisons to current weather.
Simply put, it helps you see what the weather would typically be like on this day, according to historical data.
| Daily Data | Observed | Normal | Record Highest | Record Lowest |
| Max Temperature | M | 83 | 99 in 1925 | 64 in 1943 |
| Min Temperature | M | 65 | 79 in 1925 | 45 in 1889 |
| Avg Temperature | M | 73.9 | 89.0 in 1925 | 57.0 in 1918 |
| Precipitation | M | 0.13 | 1.86 in 1999 | 0.00 in 2023 |
| Snowfall | M | 0.0 | 0.0 in 2023 | 0.0 in 2023 |
| Snow Depth | M | – | 0 in 2023 | 0 in 2023 |
| HDD (base 65) | M | 0 | 8 in 1918 | 0 in 2023 |
| CDD (base 65) | M | 9 | 24 in 1925 | 0 in 2020 |
| Month-to-Date Summary | Observed | Normal | Record Highest | Record Lowest |
| Avg Max Temperature | 83.5 | 85.2 | 95.8 in 1925 | 77.0 in 1967 |
| Avg Min Temperature | 67.9 | 67.4 | 74.6 in 1925 | 60.0 in 1967 |
| Avg Temperature | 75.7 | 76.3 | 85.2 in 1925 | 68.5 in 1967 |
| Total Precipitation | 1.15 | 2.50 | 13.27 in 1888 | 0.00 in 1897 |
| Total Snowfall | 0.0 | 0.0 | 0.0 in 2024 | 0.0 in 2024 |
| Max Snow Depth | 0 | – | 0 in 2024 | 0 in 2024 |
| Total HDD (base 65) | 0 | 1 | 20 in 1902 | 0 in 2024 |
| Total CDD (base 65) | 208 | 227 | 408 in 1925 | 81 in 1967 |
| Year-to-Date Summary | Observed | Normal | Record Highest | Record Lowest |
| Avg Max Temperature | 77.8 | 75.8 | 78.4 in 2012 | 70.1 in 1885 |
| Avg Min Temperature | 59.0 | 56.7 | 59.4 in 2023 | 50.9 in 1940 |
| Avg Temperature | 68.4 | 66.2 | 68.7 in 2012 | 61.3 in 1940 |
| Total Precipitation | 44.69 | 37.28 | 55.58 in 1920 | 22.45 in 1931 |
| Total Snowfall (since July 1) | 0.0 | 0.0 | T in 2001 | 0.0 in 2024 |
| Max Snow Depth (since July 1) | 0 | – | T in 1942 | 0 in 2024 |
| Total HDD (since July 1) | 0 | 1 | 20 in 1902 | 0 in 2024 |
| Total CDD (since Jan 1) | 2200 | 1875 | 2314 in 2019 | 1127 in 1967 |
Period of Record:
- Max Temperature : 1878-10-04 to 2024-09-19
- Min Temperature : 1878-10-04 to 2024-09-19
- Precipitation : 1878-10-01 to 2024-09-19
- Snowfall : 1928-12-25 to 2024-09-18
- Snow Depth : 1928-12-25 to 2024-09-17
For much more information on the climate in our area, visit the NWS Climate FAQ for the Atlanta area.
What does the National Weather Service do?
The National Weather Service (NWS) is a part of the National Oceanic and Atmospheric Administration (NOAA).
The NWS describes its role as follows:
“The National Weather Service (NWS) provides weather, water, and climate forecasts and warnings for the United States, its territories, adjacent waters and ocean areas, for the protection of life and property and the enhancement of the national economy.
“These services include Forecasts and Observations, Warnings, Impact-based Decision Support Services, and Education in an effort to build a Weather-Ready Nation. The ultimate goal is to have a society that is prepared for and responds to weather, water and climate events.”