Decatur, Alabama climate: Normal weather by month, frost dates and records

Decatur's normal year runs from 32°F January nights to 90°F July afternoons, with 49.5 inches of precipitation a year. (NOAA 1991-2020 normals)

In metric: a yearly mean of 16.3°C, January lows of 0°C, July highs of 32°C, 1,257 mm of precipitation a year.

  • NOAA stationDecatur Pryor Field
  • Station IDUSW00053852
  • Location34.65°N 86.95°W
  • Elevation592 ft (180 m)
  • Population57,974

On October 22, the normal high in Decatur is 72°F and the normal low 47°F, and the chance of measurable rain or snow is 29%.

Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Decatur.

  1. Jan 51° 32°
  2. Feb 55° 35°
  3. Mar 64° 42°
  4. Apr 73° 50°
  5. May 81° 59°
  6. Jun 88° 67°
  7. Jul 90° 70°
  8. Aug 90° 68°
  9. Sep 85° 61°
  10. Oct 75° 50°
  11. Nov 62° 39°
  12. Dec 54° 35°

Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.

What is the weather like in Decatur each month?

July is the warmest month, with normal highs of 90°F; January the coldest, with normal lows of 32°F. The most precipitation falls in December (5.20 in), the least in August (3.05 in).

Each month has its own page with the day-by-day normals, the month's records and its recent years:

Decatur monthly normals, 1991-2020 (°F, inches)
MonthHighLowMeanPrecip.Wet days90°F daysFreezing nightsDaylight
January 51°F32°F41.4°F 4.64 9<11710 h
February 55°F35°F45.3°F 4.96 12<11311 h
March 64°F42°F52.7°F 4.96 11<1611 h 50 min
April 73°F50°F61.6°F 4.50 11<1113 h
May 81°F59°F69.9°F 4.15 113<114 h
June 88°F67°F77.1°F 3.66 1114<114 h 30 min
July 90°F70°F79.7°F 3.95 1219<114 h 20 min
August 90°F68°F78.8°F 3.05 1118<113 h 30 min
September 85°F61°F73.1°F 3.21 89<112 h 30 min
October 75°F50°F62.0°F 3.23 91111 h 20 min
November 62°F39°F50.8°F 3.96 10<1910 h 20 min
December 54°F35°F44.1°F 5.20 11<1169 h 50 min
Year (annual)72°F51°F61.4°F49.471266462
The same normals in °C and millimetres
Decatur monthly normals, 1991-2020 (°C, mm)
MonthHighLowMeanPrecip.
January10°C0°C5.2°C118 mm
February13°C2°C7.4°C126 mm
March18°C5°C11.5°C126 mm
April23°C10°C16.4°C114 mm
May27°C15°C21.1°C105 mm
June31°C19°C25.1°C93 mm
July32°C21°C26.5°C100 mm
August32°C20°C26.0°C77 mm
September30°C16°C22.8°C82 mm
October24°C10°C16.7°C82 mm
November17°C4°C10.4°C101 mm
December12°C1°C6.7°C132 mm
Normal daily high and low by month, Decatur
Normal precipitation by month, Decatur (inches)

NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Belle Mina (2 mi N) (4 miles away), gets 1 inches of snow in a normal year; elevation and distance can change that.

Source: NOAA NCEI 1991-2020 monthly normals, station USW00053852; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.

When is the best weather to visit Decatur?

Normal highs sit between 65°F and 85°F in April, May and October. Of those, October has the fewest days with rain (9).

That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.

Source: NOAA NCEI 1991-2020 monthly normals, station USW00053852.

When is the last frost in Decatur?

In Decatur, the last spring frost (32°F) comes after March 27 in half of years and after April 10 in one year in ten; the first autumn frost comes before November 3 in half of years and before October 22 in one year in ten.

Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years

Last spring frost, half of years after
March 271 year in 10 after April 10; 9 in 10 after March 8
First autumn frost, half of years before
November 31 year in 10 before October 22; 9 in 10 before November 20

NOAA puts the median frost-free season at 221 days, and the season without a hard freeze (28°F) at 245 days.

A hard freeze (28°F) comes after March 14 in half of springs and before November 15 in half of autumns.

The USDA's 2023 Plant Hardiness Zone Map puts Decatur in zone 8a across its 3 ZIP code areas (8a in 35603, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Decatur's NOAA station is in zone 8a: the coldest night of a typical year reaches 12°F (20 complete years).

Frost dates for every NOAA station in Alabama · Frost dates by ZIP code

Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00053852; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.

What hardiness zone is each Decatur ZIP code in?

The USDA's 2023 map gives each ZIP code area one zone. Decatur's 3 ZIP code areas are all in zone 8a. Each ZIP's frost dates are in the frost tool.

Decatur ZIP code areas and their USDA 2023 Plant Hardiness Zone
ZIP codeZoneLand in Decatur
356018a44.0 km²
356038a75.6 km²
356718a12.9 km²

Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.

How hot and how cold does it get in Decatur?

In a normal year in Decatur, 64 days a year reach 90°F (2 of them 100°F or more), 62 nights fall to 32°F or colder and 126 days bring measurable precipitation.

Days at 90°F or more
64a normal year
Days at 100°F or more
2a normal year
Nights at 32°F or colder
62a normal year
Days that stay below freezing
3high of 32°F or less
Days with 0.01 inch of precipitation
126a normal year

Source: NOAA NCEI 1991-2020 annual normals, station USW00053852.

How sunny is Decatur?

Over a year 76% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Decatur, 4.4 kWh per square metre a day. August is the sunniest month (81%) and February the cloudiest (64%). Among the 459 U.S. places of 50,000 or more, that ranks tied 276th (with 27 others) in sunshine.

Decatur: sunshine by month (NASA POWER, 2001-2020)
MonthShare of clear-sky sunshineSunshine, kWh/m² a day
January69%2.5
February64%3.0
March70%4.2
April77%5.5
May77%6.0
June80%6.3
July80%6.1
August81%5.6
September80%4.9
October78%3.9
November76%2.9
December67%2.2

Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.

How much heating and cooling does Decatur need?

A normal year in Decatur brings 3,119 heating degree days, 42% fewer than the median U.S. place (5,373), and 1,828 cooling degree days, 2.0 times the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 5,114 growing degree days a year above 50°F.

Decatur: normal heating and cooling degree days by month (base 65°F)
MonthHeatingCooling
January7330
February5532
March3909
April15855
May32185
June0363
July0457
August0429
September13258
October15663
November4336
December6491
Year (annual)3,1191,828

Source: NOAA NCEI 1991-2020 monthly normals, station USW00053852. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.

Has Decatur been warmer than normal lately?

2024 averaged 64.2°F, 2.8°F above the 1991-2020 normal of 61.4°F. 1 of the 3 complete years since 2021 ran warmer than the normal.

Decatur: each recent year's mean against the 1991-2020 normal (61.4°F)
YearMeanAgainst normalPrecip.
202161.2°F−0.2°F57.11
202260.9°F−0.5°F50.19
202464.2°F+2.8°F50.17

Source: observed years: ACIS, station USW00053852. A year counts only with all twelve months complete.

How does Decatur's climate compare?

Decatur is warmer than 18 of the other 79 places with their own NOAA record in Alabama, and wetter than 0. Across the 7,247 U.S. stations with normals, its annual mean of 61.4°F is warmer than 78%.

In the Köppen classification computed from these normals, Decatur is Cfa: temperate, no dry season, hot summer. What the classes mean.

Places with the most similar year elsewhere

Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:

Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.

Which places near Decatur share this climate record?

4 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.

  • Hartselle, AL16,201 people · 15 mi S
  • Priceville, AL3,872 people · 9 mi SE
  • Trinity, AL2,602 people · 9 mi SW
  • Mooresville, AL47 people · 4 mi SE

Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.

What do Decatur's other NOAA stations record?

One more NOAA station keeps 1991-2020 normals in or near Decatur. This page uses Decatur Pryor Field; the other differs by site and elevation:

Other NOAA stations in or near Decatur: 1991-2020 normals (°F, inches)
StationFrom this stationElevationYearJan lowJul highPrecip.SnowLast frost
Decatur (4 mi SE)
USC00012209
5 mi S550 ft61.4°F31°F89°F58.0–March 26

Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.

Questions about Decatur's climate

What is the coldest month in Decatur?

January, with a normal high of 51°F and a normal low of 32°F. The warmest is July (90°F by day, 70°F at night).

Does it snow in Decatur?

Yes. NOAA publishes no 1991-2020 snowfall normal for Decatur's NOAA station; the nearest record that keeps one, Belle Mina (2 mi N) (4 miles away), records 1 inches of snow in a normal year.

What is the rainiest month in Decatur?

December, with 5.20 in of precipitation in a normal year; the driest is August with 3.05 in.

What plant hardiness zone is Decatur in?

The USDA's 2023 map puts Decatur in zone 8a across its 3 ZIP code areas (8a in 35603, the largest). By the same method at Decatur's NOAA station, the coldest night of a typical year reaches 12°F (20 years, 1991-2020): zone 8a.

How late can frost come in Decatur?

In half of years the last 32°F night comes after March 27; in one year in ten it comes after April 10. Waiting until April 10 leaves about a one-in-ten chance of a later frost.

Nearby and next

Download these normals (CSV) · JSON · How these figures are made