Annual mean 17°C · wettest around December · prevailing wind W
Warmest
30.3 °C
Coldest
8.9 °C
Wettest
36%
Windiest
4.2 m/s
Prevailing
W
3.4 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
never good
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Alpharetta over the whole year is 17°C. July is the hottest month, with highs of about 30°C; January is the coldest, with lows of about 3°C. Alpharetta has no sharply defined rainy season: the chance of rain on a given day runs from 24% in September, the driest month, to 31% in December, the wettest. Winds in Alpharetta are highest in March, averaging 2.8 m/s (10 km/h), and lightest in August, at 1.8 m/s (6 km/h). The prevailing wind is from the W. The clearest skies in Alpharetta come in October, when the sky is typically 35% covered; February is the cloudiest month, at 50%.
Month by month Alpharetta climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
9°C
3°C
5°C
29%
45%
2.7 m/s
11
0
36
February
13°C
6°C
10°C
28%
50%
2.7 m/s
27
1
58
March
17°C
8°C
13°C
29%
43%
2.8 m/s
45
2
71
April
21°C
12°C
18°C
26%
37%
2.6 m/s
65
14
65
May
25°C
17°C
24°C
28%
43%
2.4 m/s
64
44
36
June
29°C
21°C
29°C
27%
42%
2.1 m/s
30
63
7
July
30°C
23°C
32°C
26%
40%
1.9 m/s
7
53
0
August
29°C
22°C
31°C
26%
43%
1.8 m/s
14
56
3
September
27°C
19°C
28°C
24%
38%
1.8 m/s
40
56
19
October
22°C
13°C
21°C
24%
35%
2.0 m/s
71
25
56
November
16°C
8°C
13°C
26%
38%
2.2 m/s
40
3
70
December
11°C
5°C
8°C
31%
47%
2.5 m/s
16
0
50
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Alpharetta weather by season
Year round, Alpharetta has days of about 9°C at their warmest in January, its coolest month, and 30°C in July, its warmest; the coolest hours of the day run from 3°C to 23°C through the year, and the average temperature over the year is 17°C around the clock. Rain is most likely around December and least likely around September. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Alpharetta weather in winterDecember to February
High 11°CLow 5°CRain 30%
Winter in Alpharetta has typical daily highs of about 11°C and lows of about 5°C, with a 30% chance of rain on a given day.
Alpharetta weather in springMarch to May
High 21°CLow 12°CRain 28%
Spring in Alpharetta has typical daily highs of about 21°C and lows of about 12°C, with a 28% chance of rain on a given day.
Alpharetta weather in summerJune to August
High 29°CLow 22°CRain 26%
Summer in Alpharetta has typical daily highs of about 29°C and lows of about 22°C, with a 26% chance of rain on a given day.
Alpharetta weather in autumnSeptember to November
High 22°CLow 13°CRain 24%
Autumn in Alpharetta has typical daily highs of about 22°C and lows of about 13°C, with a 24% chance of rain on a given day.
When is the rainy season in Alpharetta?
Alpharetta has no sharply defined rainy season: the chance of rain on a given day runs from 24% in September, the driest month, to 31% in December, the wettest.
What time of year is Alpharetta windiest?
Winds in Alpharetta are highest in March, averaging 2.8 m/s (10 km/h), and lightest in August, at 1.8 m/s (6 km/h). The prevailing wind is from the W.
What is the average temperature in Alpharetta year round?
The average temperature in Alpharetta over the whole year is 17°C. July is the hottest month, with highs of about 30°C; January is the coldest, with lows of about 3°C.