The National Weather Service forecasts showers and thunderstorms here in Cobb County on Wednesday, September 25, 2024, with a high near 77 degrees.

The National Weather Service has issued a hazardous weather outlook for Cobb County and other parts of the region due to isolated thunderstorms that are possible along and north Georgia tonight. Also, starting at 2 p.m., much of north Georgia will be under a flood watch as Tropical Storm Helene is expected to develop into a hurricane and bear down on Georgia.

What you will read in this article

1. The extended forecast for Cobb County
2. Last month’s climate summary for the metro Atlanta region
3. The climate almanac for metro Atlanta
4. 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.

Wednesday

Showers and thunderstorms likely, then showers and possibly a thunderstorm after 4 p.m. High near 77. Southeast wind 5 to 10 mph. Chance of precipitation is 80 percent. New rainfall amounts between 1 and 2 inches possible.

Wednesday Night

Showers and possibly a thunderstorm before 7 p.m, then showers and thunderstorms likely between 7 p.m and 1 a.m, then showers likely and possibly a thunderstorm after 1 a.m. Low around 66. East wind around 10 mph, with gusts as high as 15 mph. Chance of precipitation is 80 percent. New rainfall amounts between 1 and 2 inches possible.

Thursday

Tropical storm conditions possible. Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. High near 72. Chance of precipitation is 100 percent.

Thursday Night

Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Low around 65. East wind 15 to 20 mph, with gusts as high as 40 mph. Chance of precipitation is 100 percent.

Friday

Showers and possibly a thunderstorm before 8 a.m, then a chance of showers and thunderstorms between 8 a.m and 2 p.m, then a slight chance of showers after 2 p.m. Some of the storms could produce heavy rainfall. High near 75. Windy. Chance of precipitation is 80 percent.

Friday Night

A 10 percent chance of showers before 8 p.m. Partly cloudy, with a low around 61.

Saturday

Mostly sunny, with a high near 78.

Saturday Night

Partly cloudy, with a low around 62.

Sunday

A 20 percent chance of showers after 2 p.m. Mostly sunny, with a high near 79.

Sunday Night

A 20 percent chance of showers. Partly cloudy, with a low around 62.

Monday

A 20 percent chance of showers and thunderstorms. Mostly sunny, with a high near 78.

Monday Night

A 20 percent chance of showers and thunderstorms. Partly cloudy, with a low around 62.

Tuesday

Mostly sunny, with a high near 79.

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.”

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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 25, 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	82	93 in 2019	57 in 1989
Min Temperature	M	63	74 in 2018	45 in 1887
Avg Temperature	M	72.3	82.5 in 1993	54.5 in 1989
Precipitation	M	0.13	5.30 in 1956	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	10 in 1989	0 in 2023
CDD (base 65)	M	8	18 in 1993	0 in 2015
Month-to-Date Summary	Observed	Normal	Record Highest	Record Lowest
Avg Max Temperature	85.8	84.6	95.0 in 1925	77.2 in 1918
Avg Min Temperature	68.7	66.7	74.2 in 1925	58.9 in 1967
Avg Temperature	77.2	75.6	84.6 in 1925	68.1 in 1967
Total Precipitation	1.15	3.13	14.26 in 1888	T in 1984
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	2	37 in 1918	0 in 2024
Total CDD (base 65)	300	268	496 in 1925	95 in 1967
Year-to-Date Summary	Observed	Normal	Record Highest	Record Lowest
Avg Max Temperature	78.1	75.9	78.5 in 2012	70.1 in 1885
Avg Min Temperature	59.2	56.8	59.5 in 2023	51.2 in 1940
Avg Temperature	68.7	66.3	68.9 in 2019	61.6 in 1940
Total Precipitation	44.69	37.91	56.81 in 1920	22.56 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	2	37 in 1918	0 in 2024
Total CDD (since Jan 1)	2292	1916	2381 in 2019	1141 in 1967

Period of Record:

• Max Temperature : 1878-10-04 to 2024-09-24
• Min Temperature : 1878-10-04 to 2024-09-24
• Precipitation : 1878-10-01 to 2024-09-24
• Snowfall : 1928-12-25 to 2024-09-23
• Snow Depth : 1928-12-25 to 2024-09-22

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.”