Climate and monthly weather forecast
Decatur, AL

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The climate of Decatur

Located in Northern Alabama, USA, the city of Decatur experiences a humid subtropical climate, characterized as 'Cfa' according to the Köppen climate classification, which signifies no dry season. The overall weather in Decatur exhibits consistent patterns throughout the year.

Temperature ranges from a low of 33.3°F (0.7°C) in the chilliest month of January up to a high of 88.5°F (31.4°C) in July, the hottest month. Perceptible fluctuations occur with weather parameters such as humidity, rainfall, snowfall and sunshine duration. The relative humidity remains stable, oscillating moderately between 72% and 79%.

Rainfall varies the least, with the driest month of November recording 2.48" (63mm) of rain and the wettest month, April, witnessing 4.37" (111mm). Snowfall primarily occurs only in January and February with 0.55" (14mm) and 0.24" (6mm) respectively.

Unique weather conditions include the longest duration of daylight hours in June, registering at 14.4 hours, contrasted with the shortest daylight of 9.9 hours in December. Wind speeds average 8.3mph (13.4km/h) to 4.8mph (7.7km/h) within a year without any significant gusts.

The best time to visit Decatur

The optimal time for visiting Decatur would certainly be during the moderate late spring to early summer months of May and June. During these months, the average high temperature is between 78.8°F (26°C) to 86.7°F (30.4°C), and the rainfall levels are rather on the lower side, from 3.5" (89mm) to 3.31" (84mm) respectively. Ample daylight hours of 14 to 14.4 and a comfortable relative humidity of 76% to 75% make this period the most appealing for outdoor activities and sightseeing.

The worst time to visit Decatur

The least preferable time to visit Decatur is likely during the cold winters, primarily in January. The average low temperature dips down to 33.3°F (0.7°C), significantly lowering outdoor briskness. Furthermore, despite only receiving 0.55" (14mm) of snowfall, the shorter daylight duration of 10.1 hours can hamper sightseeing and travel plans.

Spring weather in Decatur

Spring in Decatur, from March to May, progressively warms up with increasing daylight hours. Average high temperatures steadily rise from 61.3°F (16.3°C) in March to 78.8°F (26°C) in May. Average lows between 44.2°F (6.8°C) in March to 59.9°F (15.5°C) in May indicate temperate evenings. Rainfall does see a notable increase, with April being the wettest month with 4.37" (111mm) of rain recorded.

Summer weather in Decatur

The summer months from June to August typically see high temperatures, averaging between 86.7°F (30.4°C) and 88.2°F (31.2°C). July and August share similar maximum averages around 88°F (31.1°C). The minimum temperature, though warmly comfortable, spans from 67.3°F (19.6°C) in June to 69.4°F (20.8°C) in July. Even in the hottest months, rainfall still persists with the highest measure of 3.82" (97mm) observed in August.

Autumn weather in Decatur

Autumn, observed from September to November, brings about a cooling phase in Decatur. The average high temperatures drop from 83.1°F (28.4°C) in September to a cool 59.5°F (15.3°C) in November. The lower temperatures also dip from 63.7°F (17.6°C) to 42.3°F (5.7°C) within the same period. Rainfall reduces with the onset of autumn, with the least measure recorded as 2.48" (63mm) in November.

Winter weather in Decatur

Winter in Decatur, spanning from December to February, sees a pronounced dip in temperatures. The temperatures range from a low of 33.3°F (0.7°C) in January to a high of 53.1°F (11.7°C) in February. Snowfall is minimal, with the highest measure in January and February at 0.55" (14mm) and 0.24" (6mm) respectively. The daylight hours are also significantly reduced down to 9.9 hours in December. The relative humidity touches its peak at 79% in December, indicating cooler and moist conditions. Though the wind speed also rises to 8.1mph (13km/h) in December, Decatur's winter can be considered relatively mild compared to many other regions in the USA.

Weather in January

January in Decatur, Alabama, is characterized by relatively low temperatures, with the mercury ranging from 33.3°F (0.7°C) to 47.5°F (8.6°C). It becomes chillier compared to December. The colder days encourage more indoor activities and outdoor winter preparations. Weather in January »

Weather in February

February preserves the impressions of January, but warms up slightly, providing a hint of the advancing spring. The lowest temperature note is 37.2°F (2.9°C) and the highest reaches up to 53.1°F (11.7°C), showcasing the minor but notable rise from the previous month. Weather in February »

Weather in March

Switching to spring in March, it ushers a noticeable transition in weather conditions in Decatur. The upward swing on the thermometer from 44.2°F (6.8°C) to 61.3°F (16.3°C) indicates the faster pace towards warmth. The snowfall disappears altogether, taking with it the wistful memories of winter. Weather in March »

Weather in April

April brings milder weather to Decatur, with the temperature rising from 51.4°F (10.8°C) to 70.5°F (21.4°C), signaling full immersion in Spring. The city sees a surge in the amount of sunshine and daylight hours allows for a longer period of outdoor activities. Weather in April »

Weather in May

May is marked by a significant warmth in Decatur, with temperatures ranging from 59.9°F (15.5°C) to 78.8°F (26°C), implying a pleasant presage of summer. With the reduction in cloud cover, the abundant sunshine further adds to the warmth. Weather in May »

Weather in June

June welcomes balmy summer in Decatur, escalating the heat from the low of 67.3°F (19.6°C) to 86.7°F (30.4°C) high, a noticeable jump from May. It is the month that enjoys the longest day in a year, bringing maximum hours of sunshine. Weather in June »

Weather in July

July signifies the peak of summer in Decatur, with a temperature rise from 69.4°F (20.8°C) to 88.5°F (31.4°C), the highest recorded in the year. Days in July also pack in slightly less sunshine compared to June. Although rainfall is consistent, it is insufficient to dampen the summer enthusiasm. Weather in July »

Weather in August

August maintains the summer spirit in Decatur, with temperatures sustaining from 68.9°F (20.5°C) to 88.2°F (31.2°C), showcasing a steady hold from July. The daylight hours start to shrink, hinting the approaching autumn but the city continues to bask under ample sunshine. Weather in August »

Weather in September

September marks the transition from summer to autumn in Decatur, showcasing a wide temperature swing from 63.7°F (17.6°C) to 83.1°F (28.4°C). The city witnesses a level of cloud cover reduction, allowing sunshine to pour generously over the landscapes. Weather in September »

Weather in October

October brings profound autumn weather to Decatur, with temperatures taking a dip, registering between 52.7°F (11.5°C) and 72.1°F (22.3°C). The decrease in temperature from the previous month sets the tone for incoming chill. Weather in October »

Weather in November

November ushers in late autumn in Decatur, cooling down further with temperatures spanning from 42.3°F (5.7°C) to 59.5°F (15.3°C). This month offers the clearest visibility, laying out perfect conditions for outdoor exploration. Weather in November »

Weather in December

December in Decatur kicks off the winter season, displaying temperatures from 38.3°F (3.5°C) to 51.6°F (10.9°C), solidifying the departure from the milder conditions in November. The city sees a revival of snowfall, although light, it still ushering the joyous period of Christmas celebrations. Weather in December »
Updated: Aug 30, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What time of the year is the coldest?

In Decatur, January records the average lowest temperatures, peaking at 47.5°F (8.6°C) and reaching a low of 33.3°F (0.7°C).

How many days does it rain in Decatur?

In Decatur, during the entire year, the rain falls for 177.6 days and collects up to 43.11" (1095mm) of precipitation.

When does it snow in Decatur?

Months with snowfall are January through March, November and December.

When does it snow the most?

The months with the most snowfall are January and February, with an average 0.55" (14mm) of accumulated snow.

How much does it snow in Decatur?

In Decatur, during the entire year, snow falls for 7.4 days and aggregates up to 1.77" (45mm) of snow.

What are the months with the lowest UV index?

The months with the lowest UV index are January and December, with an average maximum UV index of 2.

What is the month with the least sunshine?

February has the least sunshine of the year in Decatur, with an average of 4.6h of sunshine.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from CST to CDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from CDT to CST.

When it does not snow in Decatur?

In Decatur, snow does not fall in April through October.

When is the highest UV index?

May through August, with an average maximum UV index of 6, are months with the highest UV index.

When are the longest days?

With an average of 14h and 24min of daylight, June has the longest days of the year.

What month has the most sunshine?

With an average of 10.5h of sunshine, June has the most sunshine of the year.

What time of the year is the hottest?

Decatur's warmest weather arrives in July, when temperatures average a high of 88.5°F (31.4°C) and a low of 69.4°F (20.8°C).

What is the driest month?

The months with the least rainfall are September and November Rain falls for 13.8 days and accumulates 2.48" (63mm) of rain.

What is the least humid month?

October is the least humid month, with an average relative humidity of 72%.

What is the most humid month?

The most humid month is December, with an average relative humidity of 79%.

What is the wettest month?

December is the month with the most rainfall. Rain falls for 13.3 days and accumulates 4.45" (113mm) of precipitation.

What is the month with the shortest days?

With an average of 9h and 54min of daylight, December has the shortest days of the year.

Average temperature
Decatur, AL

Average temperature - Decatur, AL

The warmest month (with the highest average high temperature) is July (88.5°F).
The month with the lowest average high temperature is January (47.5°F).

The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (33.3°F).

Average pressure
Decatur, AL

Average pressure - Decatur, AL

The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).

Average wind speed
Decatur, AL

Average wind speed - Decatur, AL

The windiest month (with the highest average wind speed) is February (8.6mph).
The calmest month (with the lowest average wind speed) is July (4.8mph).

Average humidity
Decatur, AL

Average humidity - Decatur, AL

The month with the highest relative humidity is December (79%).
The month with the lowest relative humidity is October (72%).

Average rainfall
Decatur, AL

Average rainfall - Decatur, AL

The wettest month (with the highest rainfall) is December (4.45").
The driest months (with the least rainfall) are September and November (2.48").

Average rainfall days
Decatur, AL

Average rainfall days - Decatur, AL

The month with the highest number of rainy days is July (20 days).
The month with the least rainy days is November (10.4 days).

Average snowfall
Decatur, AL

Average snowfall - Decatur, AL

The months with the highest snowfall are January and February (0.55").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days
Decatur, AL

Average snowfall days - Decatur, AL

The month with the highest number of snowfall days is February (2.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight / Average sunshine
Decatur, AL

Average daylight / Average sunshine - Decatur, AL

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).

The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).

Average sunshine days
Decatur, AL

Average sunshine days - Decatur, AL

The month with the most sunshine days is October (19.2 days).
The month with the least sunshine days is July (8.8 days).

Average UV index
Decatur, AL

Average UV index - Decatur, AL

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 visibility
Decatur, AL

Average visibility - Decatur, AL

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).

Decatur, Alabama, USA

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