Round Spring (2 mi SW), Missouri climate: Climate normals at a NOAA weather station
Round Spring (2 mi SW)'s normal year runs from 20°F January nights to 90°F July afternoons, with 49.1 inches of precipitation and 6 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.9°C, January lows of −6°C, July highs of 32°C, 1,248 mm of precipitation a year.
- NOAA stationRound Spring (2 mi SW)
- Station IDUSC00237309
- Location37.26°N 91.43°W
- Elevation829 ft (253 m)
On October 23, the normal high in Round Spring (2 mi SW) is 68°F and the normal low 38°F, and the chance of measurable rain or snow is 27%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Round Spring (2 mi SW).
- Jan 45° 20°
- Feb 50° 23°
- Mar 60° 32°
- Apr 71° 40°
- May 78° 51°
- Jun 85° 60°
- Jul 90° 65°
- Aug 88° 63°
- Sep 81° 54°
- Oct 71° 41°
- Nov 59° 32°
- Dec 47° 24°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Round Spring (2 mi SW) each month?
July is the warmest month, with normal highs of 90°F; January the coldest, with normal lows of 20°F. The most precipitation falls in May (6.16 in), the least in January (2.66 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 45°F | 20°F | 32.8°F | 2.66 | 1.0 | 7 | <1 | 27 | 9 h 50 min |
| February | 50°F | 23°F | 36.3°F | 3.60 | 2.6 | 9 | <1 | 24 | 10 h 50 min |
| March | 60°F | 32°F | 45.8°F | 4.08 | 1.4 | 10 | <1 | 18 | 11 h 50 min |
| April | 71°F | 40°F | 55.5°F | 4.83 | 0.0 | 9 | <1 | 8 | 13 h 10 min |
| May | 78°F | 51°F | 64.2°F | 6.16 | 0.0 | 12 | 1 | 1 | 14 h 10 min |
| June | 85°F | 60°F | 72.7°F | 4.28 | 0.0 | 10 | 9 | <1 | 14 h 40 min |
| July | 90°F | 65°F | 77.2°F | 4.60 | 0.0 | 9 | 17 | <1 | 14 h 30 min |
| August | 88°F | 63°F | 75.5°F | 4.35 | 0.0 | 9 | 13 | <1 | 13 h 40 min |
| September | 81°F | 54°F | 67.5°F | 3.79 | 0.0 | 8 | 5 | <1 | 12 h 30 min |
| October | 71°F | 41°F | 55.9°F | 3.28 | 0.0 | 8 | <1 | 8 | 11 h 20 min |
| November | 59°F | 32°F | 45.0°F | 4.06 | 0.2 | 8 | <1 | 18 | 10 h 10 min |
| December | 47°F | 24°F | 35.5°F | 3.46 | 0.4 | 8 | <1 | 25 | 9 h 40 min |
| Year (annual) | 69°F | 42°F | 55.3°F | 49.15 | 5.6 | 107 | 47 | 129 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 7°C | −6°C | 0.4°C | 68 mm | 3 cm |
| February | 10°C | −5°C | 2.4°C | 91 mm | 7 cm |
| March | 15°C | 0°C | 7.7°C | 104 mm | 4 cm |
| April | 21°C | 5°C | 13.1°C | 123 mm | 0 cm |
| May | 25°C | 10°C | 17.9°C | 156 mm | 0 cm |
| June | 30°C | 16°C | 22.6°C | 109 mm | 0 cm |
| July | 32°C | 18°C | 25.1°C | 117 mm | 0 cm |
| August | 31°C | 17°C | 24.2°C | 110 mm | 0 cm |
| September | 27°C | 12°C | 19.7°C | 96 mm | 0 cm |
| October | 22°C | 5°C | 13.3°C | 83 mm | 0 cm |
| November | 15°C | 0°C | 7.2°C | 103 mm | 1 cm |
| December | 8°C | −5°C | 1.9°C | 88 mm | 1 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00237309; 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.
Which months are mildest at Round Spring (2 mi SW)?
Normal highs sit between 65°F and 85°F in April, May, September and October. Of those, September has the fewest days with rain (8).
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 USC00237309.
When is the last frost at Round Spring (2 mi SW)?
In Round Spring (2 mi SW), the last spring frost (32°F) comes after April 24 in half of years and after May 8 in one year in ten; the first autumn frost comes before October 16 in half of years and before October 4 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
- April 241 year in 10 after May 8; 9 in 10 after April 10
- First autumn frost, half of years before
- October 161 year in 10 before October 4; 9 in 10 before October 28
NOAA puts the median frost-free season at 172 days, and the season without a hard freeze (28°F) at 194 days.
A hard freeze (28°F) comes after April 13 in half of springs and before October 25 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Round Spring (2 mi SW) in zone 6b in ZIP code 65466, the nearest ZIP area.
Frost dates for every NOAA station in Missouri · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00237309; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get at Round Spring (2 mi SW)?
In a normal year in Round Spring (2 mi SW), 47 days a year reach 90°F (3 of them 100°F or more), 129 nights fall to 32°F or colder and 107 days bring measurable precipitation.
- Days at 90°F or more
- 47a normal year
- Days at 100°F or more
- 3a normal year
- Nights at 32°F or colder
- 129a normal year
- Days that stay below freezing
- 12high of 32°F or less
- Days with 0.01 inch of precipitation
- 107a normal year
- Days with 1 inch of snow or more
- 2a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00237309.
How sunny is it at Round Spring (2 mi SW)?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds at Round Spring (2 mi SW), 4.3 kWh per square metre a day. July is the sunniest month (82%) and February the cloudiest (67%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 69% | 2.3 |
| February | 67% | 3.0 |
| March | 68% | 4.0 |
| April | 72% | 5.1 |
| May | 73% | 5.7 |
| June | 81% | 6.6 |
| July | 82% | 6.4 |
| August | 80% | 5.6 |
| September | 81% | 4.8 |
| October | 76% | 3.6 |
| November | 73% | 2.5 |
| December | 67% | 2.0 |
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 many heating and cooling degree days does Round Spring (2 mi SW) record?
A normal year at Round Spring (2 mi SW) brings 4,712 heating degree days, 12% fewer than the median U.S. place (5,373), and 1,218 cooling degree days, 34% more than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,881 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,000 | 0 |
| February | 802 | 0 |
| March | 598 | 3 |
| April | 306 | 21 |
| May | 108 | 83 |
| June | 9 | 239 |
| July | 1 | 379 |
| August | 3 | 330 |
| September | 63 | 138 |
| October | 306 | 24 |
| November | 602 | 2 |
| December | 914 | 0 |
| Year (annual) | 4,712 | 1,218 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00237309. 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.
Have recent years at Round Spring (2 mi SW) been warmer than normal?
2025 averaged 56.8°F, 1.5°F above the 1991-2020 normal of 55.3°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 55.4°F | +0.1°F | 49.02 | 15.6 |
| 2022 | 54.8°F | −0.5°F | 43.66 | 14.5 |
| 2023 | 57.2°F | +1.9°F | – | – |
| 2025 | 56.8°F | +1.5°F | 46.49 | – |
Source: observed years: ACIS, station USC00237309. A year counts only with all twelve months complete.
How does Round Spring (2 mi SW)'s climate compare?
Round Spring (2 mi SW) is warmer than 67 of the 134 places with their own NOAA record in Missouri, and wetter than 115. Across the 7,247 U.S. stations with normals, its annual mean of 55.3°F is warmer than 61%.
In the Köppen classification computed from these normals, Round Spring (2 mi SW) 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 Round Spring (2 mi SW) share this climate record?
Bunker has no NOAA station with 1991-2020 normals of its 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.
- Bunker, MO297 people · 18 mi NE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Round Spring (2 mi SW)'s climate
What is the coldest month at Round Spring (2 mi SW)?
January, with a normal high of 45°F and a normal low of 20°F. The warmest is July (90°F by day, 65°F at night).
Does it snow at Round Spring (2 mi SW)?
Yes: 6 inches in a normal year, falling on 4 days with 0.1 inch or more, the most in February (2.6 inches).
What is the rainiest month at Round Spring (2 mi SW)?
May, with 6.16 in of precipitation in a normal year; the driest is January with 2.66 in.
What plant hardiness zone is Round Spring (2 mi SW) in?
The USDA's 2023 map puts Round Spring (2 mi SW) in zone 6b in ZIP code 65466, the nearest ZIP area.
How late can frost come at Round Spring (2 mi SW)?
In half of years the last 32°F night comes after April 24; in one year in ten it comes after May 8. Waiting until May 8 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Missouri climateThe statewide normals and every place in the state
- Eminence, MO8 miles from this station, 56.6°F a year
- Summersville, MO14 miles from this station, 56.0°F a year
- Winona, MO19 miles from this station, 54.0°F a year
- Salem, MO27 miles from this station, 55.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made