Seymour weather by month
What a typical year looks like in Seymour, Missouri: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Ava 6nw, 15 km from Seymour; records cover 2006–2026.
The year at a glance
- Precipitation a year
- 48.5 in1231 mm
- Snow a year
- Rare
- Last spring freeze
- Apr 18
- First fall freeze
- Oct 20
- Heating degree days
- 4,825
- Cooling degree days
- 1,156
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 6°−14° (heating, 99%) and 100°38° (cooling, 1%).
Month by month
Seymour in January
Highs average 44°7° and lows 20°−7°, with 3.1 in78 mm of precipitation in a typical January.
- Record high
- 74°23° (2008)
- Record low
- −15°−26° (2014)
- Heating degree days
- 1027
- Cooling degree days
- 0
Seymour in February
Highs average 48°9° and lows 23°−5°, with 2.8 in70 mm of precipitation in a typical February.
- Record high
- 85°29° (2024)
- Record low
- −14°−26° (2015)
- Heating degree days
- 829
- Cooling degree days
- 0
Seymour in March
Highs average 58°15° and lows 32°0°, with 4.3 in109 mm of precipitation in a typical March.
- Record high
- 94°34° (2026)
- Record low
- 1°−17° (2014)
- Heating degree days
- 619
- Cooling degree days
- 2
Seymour in April
Highs average 68°20° and lows 41°5°, with 5.2 in131 mm of precipitation in a typical April.
- Record high
- 90°32° (2011)
- Record low
- 19°−7° (2007)
- Heating degree days
- 333
- Cooling degree days
- 12
Seymour in May
Highs average 76°24° and lows 52°11°, with 5.6 in142 mm of precipitation in a typical May.
- Record high
- 95°35° (2012)
- Record low
- 31°−1° (2020)
- Heating degree days
- 109
- Cooling degree days
- 83
Seymour in June
Highs average 84°29° and lows 60°15°, with 4.5 in115 mm of precipitation in a typical June.
- Record high
- 106°41° (2012)
- Record low
- 46°8° (2009)
- Heating degree days
- 7
- Cooling degree days
- 215
Seymour in July
Highs average 89°31° and lows 65°18°, with 4.3 in109 mm of precipitation in a typical July.
- Record high
- 107°42° (2011)
- Record low
- 49°9° (2013)
- Heating degree days
- 0
- Cooling degree days
- 361
Seymour in August
Highs average 88°31° and lows 63°17°, with 3.9 in99 mm of precipitation in a typical August.
- Record high
- 104°40° (2011)
- Record low
- 47°8° (2015)
- Heating degree days
- 2
- Cooling degree days
- 327
Seymour in September
Highs average 81°27° and lows 54°12°, with 4.1 in104 mm of precipitation in a typical September.
- Record high
- 101°38° (2026)
- Record low
- 37°3° (2006)
- Heating degree days
- 55
- Cooling degree days
- 131
Seymour in OctoberThis month
Highs average 70°21° and lows 42°6°, with 3.7 in94 mm of precipitation in a typical October.
- Record high
- 92°33° (2006)
- Record low
- 16°−9° (2017)
- Heating degree days
- 295
- Cooling degree days
- 24
Seymour in November
Highs average 57°14° and lows 31°−1°, with 4 in102 mm of precipitation in a typical November.
- Record high
- 86°30° (2023)
- Record low
- 5°−15° (2014)
- Heating degree days
- 636
- Cooling degree days
- 1
Seymour in December
Highs average 47°8° and lows 24°−4°, with 3.1 in77 mm of precipitation in a typical December.
- Record high
- 72°22° (2006)
- Record low
- 1°−17° (2008)
- Heating degree days
- 913
- Cooling degree days
- 0