Climate and monthly weather forecastAlpharetta, GA
Climate and monthly weather forecast
The climate of Alpharetta
Positioned in a geographic location where the climate constitutes predominantly Humid Subtropical according to the Köppen climate classification, Alpharetta rewards its residents with a climate where rainfall is evenly distributed throughout the year, and there is no defined dry season. Thermally, Alpharetta's temperature highs fluctuate from 49.1°F (9.5°C) to 90°F (32.2°C), with July presenting the warmest weather. The temperature lows, on the other hand, trim down to as low as 33.6°F (0.9°C) during January.The annual humid condition stands out with an average relative humidity that ranges from 69% in July and August to 78% in December. Even at its lowest, the humidity level in Alpharetta prevails noticeably high. An examination of precipitation indicates that rainfall levels oscillate between 1.34" (34mm) in October and 3.58" (91mm) in August. Rainfall days fall within the frame of 9 in November to 18.8 in July, illustrating a relatively rainy city character.
Trivial amounts of snowfall barely exceeding half an inch in January and December grace Alpharetta, complemented by an insignificant number of snowfall days which do not cross the 1.5 per month threshold. Thus, Alpharetta experiences mild to non-existent snow events. The annual daylight duration varies from 9.9 hours in December to 14.4 hours in June, and sunshine hours fluctuate between 5.1 in December and 10.6 in July.
The best time to visit Alpharetta
The idyllic period to explore Alpharetta appears to align with the harmonic convergence of prolonged daylight hours, relatively lower rainfall, and manageable temperatures. This period spans from late spring to early summer, mainly May to June. During these times, visitors can observe extended daylight hours spanning from 13.9 to 14.4, peak sunshine hours from 9.8 to 10.5, and a moderate average rainfall between 2.68" (68mm) to 2.2" (56mm) coupled with average monthly rainfall days, at best, only touching 16.3 hours.The worst time to visit Alpharetta
Contrarily, the exploration of Alpharetta can be daunting throughout late summer with sweltering temperatures and high rainfall measures dominating the scene. August presents the most challenging conditions with an unrelenting average high temperature of 88.7°F (31.5°C) and rainfall measure striking at a peak of 3.58" (91mm).Spring weather in Alpharetta
The springtime in Alpharetta ushers with a gradual transition from the chills of winter to the warmth of summer. The period covering March to May witnesses a surge in temperature, with the daytime temperature climbing from 61.9°F (16.6°C) to 79.5°F (26.4°C). Concurrently, nighttime temperatures elevate between 44.2°F (6.8°C) and 60.4°F (15.8°C). Rainfall persists at an average level, varying from 1.93" (49mm) to 2.68" (68mm), and sets up 12.6 to 16.3 rainy days per month.Summer weather in Alpharetta
Alpharetta dazzles with its hot summer weather, discernible between June and August. Summer days in the city are notably long with daylight prolonging between 13.9 to 14.4 hours. Simultaneously, the temperatures soar from 79.5°F (26.4°C) to 90°F (32.2°C), and nighttime temperatures fluctuate within a relatively warm range of 60.4°F (15.8°C) to 70.3°F (21.3°C). Rainfall during this season peaks at 3.58" (91mm) in August while settling at 2.2" (56mm) in June.Autumn weather in Alpharetta
As summer retreats and temperatures begin to dip, Alpharetta experiences autumn between September and November. Witness the daytime temperatures descending from 83.5°F (28.6°C) in September to a relatively cooler 60.1°F (15.6°C) in November. Nights cool down with temperatures dropping from 64.8°F (18.2°C) to 42.8°F (6°C). Rainfall during autumn measures between 1.57" (40mm) and 1.85" (47mm), with the number of rainy days settling around 9 to 11 days per month.Winter weather in Alpharetta
Winter spans from December until February, with temperatures hitting the year’s lowest. Daytime temperatures fall between 49.1°F (9.5°C) and 54.1°F (12.3°C), while nighttime temperatures emulate the chilling trend, dropping between 33.6°F (0.9°C) and 37.8°F (3.2°C). Rainfall during this season stays consistent, registering between 1.57" (40mm) to 2.09" (53mm). A touch of snow adorns Alpharetta with measures rarely exceeding half an inch and snowfall days barely crossing 1.5 per month.Weather in January
January in Alpharetta, Georgia, greets the New Year with cool weather and chilly nights with temperatures fluctuating between 33.6°F (0.9°C) and 49.1°F (9.5°C). The climate sees a fair amount of rainfall, marking the onset of a soggy period, while a light dusting of snow is not uncommon. Weather in January »Weather in February
Alpharetta's weather in February exhibits a slight warmth with temperatures rising from January's cool range. While the amount of daily sunlight begins to increase, the rainfall inches up making it a wet month. Contrary to the preceding month, the chances of experiencing snowfall decline significantly. Weather in February »Weather in March
March indicates the transition phase towards warmer weather in Alpharetta, with fewer cloudy days than February. As the month witnesses a rise in temperature and a spike in rainfall, the relative humidity remains constant. Vulnerability to snow reduces further, hinting at the farewell to wintry conditions. Weather in March »Weather in April
April in Alpharetta sees consistent warming with reduced nightly chills, featuring temperatures ranging from 52.3°F (11.3°C) to 71.4°F (21.9°C). Compared to March, the rainfall increases slightly, suggesting a further rise in humidity. Weather in April »Weather in May
May in Alpharetta marks the city's journey into the warm season, with heightened temperatures and humidity. Rainfall continues its upward trend from April, with weather patterns suggesting damp conditions. The sharp increase in the average daylight period of 13.9 hours confirms the proximity of summer. Weather in May »Weather in June
June introduces the summer season in Alpharetta, when the temperature reaches up to 87.1°F (30.6°C). An increased number of sunny days contribute to extended hours of daylight, resulting in warmer conditions. Despite the rise in temperatures, the rainfall sees a small dip compared to May, providing respite from excessive wetness. Weather in June »Weather in July
July signifies peak summer in Alpharetta, with an average high of 90°F (32.2°C). The weather remains sunny with extended daylight duration and high UV index, compelling Alpharetta's residents to seek shade frequently. A surge in rainfall distinguishes July as the wettest month of the year, contributing to pleasant evenings. Weather in July »Weather in August
August weather in Alpharetta is largely similar to July, featuring high temperatures and significant rain showers. As the month progresses, there's a slight dip in temperature, suggestive of upcoming autumn. Though rainfall slightly exceeds that of July, the overall percentage of cloud cover decreases, promising brighter days. Weather in August »Weather in September
September in Alpharetta marks the onset of fall, with drastically reduced temperatures from August highs of 88.7°F (31.5°C). A sharp decline in rainfall from August maxima indicates the waning of the damp phase. As the percentage of cloud cover remains the same, the amount of daylight begins to reduce, signaling shorter days ahead. Weather in September »Weather in October
In October, Alpharetta embraces the essence of autumn, with a substantial temperature difference from the September highs of 83.5°F (28.6°C). The noticeable drop in rainfall affirms the cessation of the rainy season. Shortened daylight hours and an increment in wind speed reinforce the cool ambiance of fall. Weather in October »Weather in November
November carries forward the autumn spirit in Alpharetta, with a slight chill hinting at the advent of winter. A surge in rainfall after the dry October conditions suggests a return of moisture in the atmosphere. The daylight duration further lessens, resulting in early sunsets. Weather in November »Weather in December
December in Alpharetta witnesses a full swing into winter, with temperatures fluctuating between 38.7°F (3.7°C) and 53.1°F (11.7°C). The consistent rise in rainfall from November readings results in fairly wet conditions. Reduced daylight and increased cloud cover confirms December's position as an overcast month. Weather in December »Updated: Feb 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
With an average high-temperature of 49.1°F (9.5°C) and an average low-temperature of 33.6°F (0.9°C), January is the coldest month in Alpharetta.
In Alpharetta, during the entire year, the rain falls for 158.7 days and collects up to 26.06" (662mm) of precipitation.
Months with snowfall in Alpharetta, Georgia, are January through March, November and December.
January is the month with the most snowfall in Alpharetta, Georgia. Snow falls for 1.3 days and accumulates 0.71" (18mm) of snow.
Throughout the year, there are 4.1 snowfall days, and 1.77" (45mm) of snow is accumulated.
The months with the lowest UV index are January and December, with an average maximum UV index of 2.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Alpharetta, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.
April through October are months without snowfall in Alpharetta, Georgia.
The months with the highest UV index in Alpharetta are May through August, with an average maximum UV index of 6.
June has the longest days of the year in Alpharetta, Georgia, with an average of 14h and 24min of daylight.
July proves to be the warmest month, recording an average peak temperature of 90°F (32.2°C) and a minimum temperature of 70.3°F (21.3°C).
The months with the lowest humidity in Alpharetta, Georgia, are July and August, with an average relative humidity of 69%.
The month with the most sunshine is July, with an average of 10.6h of sunshine.
August is the month with the most rainfall. Rain falls for 18.1 days and accumulates 3.58" (91mm) of precipitation.
October is the month with the least rainfall. Rain falls for 9 days and accumulates 1.34" (34mm) of precipitation.
The most humid month is December, with an average relative humidity of 78%.
With an average of 9h and 54min of daylight, December has the shortest days of the year.
December has the least sunshine of the year, with an average of 5.1h of sunshine.
Average temperature
Alpharetta, GA
The warmest month (with the highest average high temperature) is July (90°F).
The month with the lowest average high temperature is January (49.1°F).
The month with the highest average low temperature is July (70.3°F).
The coldest month (with the lowest average low temperature) is January (33.6°F).
Average pressure
Alpharetta, GA
- Average pressure in January:
30.16"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.1"Hg - Average pressure in April:
30.02"Hg - Average pressure in May:
30.03"Hg - Average pressure in June:
29.99"Hg
- Average pressure in July:
30.01"Hg - Average pressure in August:
30.01"Hg - Average pressure in September:
30.03"Hg - Average pressure in October:
30.06"Hg - Average pressure in November:
30.15"Hg - Average pressure in December:
30.15"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.99"Hg).
Average wind speed
Alpharetta, GA
- Average wind speed in January:
7.8mph - Average wind speed in February:
7.7mph - Average wind speed in March:
7.3mph - Average wind speed in April:
7.1mph - Average wind speed in May:
5.7mph - Average wind speed in June:
5mph
- Average wind speed in July:
4.6mph - Average wind speed in August:
4.5mph - Average wind speed in September:
4.8mph - Average wind speed in October:
6mph - Average wind speed in November:
6.5mph - Average wind speed in December:
7.2mph
The windiest month (with the highest average wind speed) is January (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity
Alpharetta, GA
The month with the highest relative humidity is December (78%).
The months with the lowest relative humidity are July and August (69%).
Average rainfall
Alpharetta, GA
- Average rainfall in January:
1.57" - Average rainfall in February:
1.89" - Average rainfall in March:
1.93" - Average rainfall in April:
2.13" - Average rainfall in May:
2.68" - Average rainfall in June:
2.2"
- Average rainfall in July:
3.23" - Average rainfall in August:
3.58" - Average rainfall in September:
1.57" - Average rainfall in October:
1.34" - Average rainfall in November:
1.85" - Average rainfall in December:
2.09"
The wettest month (with the highest rainfall) is August (3.58").
The driest month (with the least rainfall) is October (1.34").
Average rainfall days
Alpharetta, GA
- Average rainfall days in January:
10.3 days - Average rainfall days in February:
11.2 days - Average rainfall days in March:
13.8 days - Average rainfall days in April:
12.6 days - Average rainfall days in May:
16.3 days - Average rainfall days in June:
16.3 days
- Average rainfall days in July:
18.8 days - Average rainfall days in August:
18.1 days - Average rainfall days in September:
11.5 days - Average rainfall days in October:
9 days - Average rainfall days in November:
9.4 days - Average rainfall days in December:
11.4 days
The month with the highest number of rainy days is July (18.8 days).
The month with the least rainy days is October (9 days).
Average snowfall
Alpharetta, GA
The month with the highest snowfall is January (0.71").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days
Alpharetta, GA
- Average snowfall days in January:
1.3 days - Average snowfall days in February:
1.5 days - Average snowfall days in March:
0.3 days - Average snowfall days in April:
0.1 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0.1 days - Average snowfall days in December:
0.8 days
The month with the highest number of snowfall days is February (1.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight / Average sunshine
Alpharetta, GA
- Average daylight in January:
10h and 12min - Average daylight in February:
11h and 0min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 6min - Average daylight in May:
13h and 54min - Average daylight in June:
14h and 24min
- Average daylight in July:
14h and 12min - Average daylight in August:
13h and 24min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 18min - Average daylight in November:
10h and 24min - Average daylight in December:
9h and 54min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in January:
5h and 36min - Average sunshine in February:
6h and 24min - Average sunshine in March:
6h and 54min - Average sunshine in April:
8h and 30min - Average sunshine in May:
9h and 48min - Average sunshine in June:
10h and 30min
- Average sunshine in July:
10h and 36min - Average sunshine in August:
9h and 30min - Average sunshine in September:
8h and 36min - Average sunshine in October:
7h and 6min - Average sunshine in November:
5h and 48min - Average sunshine in December:
5h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).
Average sunshine days
Alpharetta, GA
- Average sunshine days in January:
18.8 days - Average sunshine days in February:
14.6 days - Average sunshine days in March:
15 days - Average sunshine days in April:
15.4 days - Average sunshine days in May:
12.8 days - Average sunshine days in June:
11.3 days
- Average sunshine days in July:
10.1 days - Average sunshine days in August:
10.8 days - Average sunshine days in September:
16.7 days - Average sunshine days in October:
20.5 days - Average sunshine days in November:
19.3 days - Average sunshine days in December:
18.1 days
The month with the most sunshine days is October (20.5 days).
The month with the least sunshine days is July (10.1 days).
Average UV index
Alpharetta, GA
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover
Alpharetta, GA
The months with the most cloud cover are February and December (Cloud cover 46).
The month with the least cloud cover is June (Cloud cover 30).
Average visibility
Alpharetta, GA
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
