Byron, Minnesota climate: Normal weather by month, frost dates and records
Byron's normal year runs from 4°F January nights to 81°F July afternoons, with 36.0 inches of precipitation and 44 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 6.3°C, January lows of −16°C, July highs of 27°C, 914 mm of precipitation a year.
- NOAA stationByron 4NORTH
- Station IDUSC00211174
- Location44.09°N 92.64°W
- Elevation1,041 ft (317 m)
- Population6,809
On October 14, the normal high in Byron is 59°F and the normal low 34°F, and the chance of measurable rain or snow is 30%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Byron.
- Jan 23° 4°
- Feb 27° 6°
- Mar 40° 20°
- Apr 55° 32°
- May 68° 44°
- Jun 78° 55°
- Jul 81° 58°
- Aug 79° 55°
- Sep 72° 47°
- Oct 58° 34°
- Nov 42° 23°
- Dec 28° 11°
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 Byron each month?
July is the warmest month, with normal highs of 81°F; January the coldest, with normal lows of 4°F. The most precipitation falls in June (5.27 in), the least in January (1.02 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 23°F | 4°F | 13.0°F | 1.02 | 8.8 | 7 | <1 | 31 | 9 h 10 min |
| February | 27°F | 6°F | 16.8°F | 1.12 | 9.6 | 6 | <1 | 27 | 10 h 30 min |
| March | 40°F | 20°F | 30.0°F | 2.09 | 8.8 | 8 | <1 | 26 | 11 h 50 min |
| April | 55°F | 32°F | 43.3°F | 3.62 | 1.2 | 10 | <1 | 17 | 13 h 20 min |
| May | 68°F | 44°F | 55.7°F | 4.31 | 0.6 | 13 | 1 | 4 | 14 h 40 min |
| June | 78°F | 55°F | 66.2°F | 5.27 | 0.0 | 14 | 2 | <1 | 15 h 30 min |
| July | 81°F | 58°F | 69.7°F | 4.63 | 0.0 | 11 | 3 | <1 | 15 h 10 min |
| August | 79°F | 55°F | 67.2°F | 4.80 | 0.0 | 11 | 1 | <1 | 14 h |
| September | 72°F | 47°F | 59.4°F | 3.47 | 0.0 | 10 | 1 | 2 | 12 h 40 min |
| October | 58°F | 34°F | 45.9°F | 2.44 | 0.1 | 9 | <1 | 15 | 11 h 10 min |
| November | 42°F | 23°F | 32.3°F | 1.90 | 2.8 | 6 | <1 | 24 | 9 h 40 min |
| December | 28°F | 11°F | 19.7°F | 1.32 | 12.5 | 7 | <1 | 30 | 8 h 50 min |
| Year (annual) | 54°F | 32°F | 43.3°F | 35.99 | 44.4 | 111 | 8 | 176 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −5°C | −16°C | −10.6°C | 26 mm | 22 cm |
| February | −3°C | −14°C | −8.4°C | 28 mm | 24 cm |
| March | 5°C | −7°C | −1.1°C | 53 mm | 22 cm |
| April | 13°C | 0°C | 6.3°C | 92 mm | 3 cm |
| May | 20°C | 7°C | 13.2°C | 109 mm | 2 cm |
| June | 26°C | 13°C | 19.0°C | 134 mm | 0 cm |
| July | 27°C | 15°C | 20.9°C | 118 mm | 0 cm |
| August | 26°C | 13°C | 19.6°C | 122 mm | 0 cm |
| September | 22°C | 8°C | 15.2°C | 88 mm | 0 cm |
| October | 15°C | 1°C | 7.7°C | 62 mm | 0 cm |
| November | 5°C | −5°C | 0.2°C | 48 mm | 7 cm |
| December | −2°C | −12°C | −6.8°C | 34 mm | 32 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00211174; 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 Byron?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (10).
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 USC00211174.
When is the last frost in Byron?
In Byron, the last spring frost (32°F) comes after May 12 in half of years and after May 25 in one year in ten; the first autumn frost comes before September 28 in half of years and before September 14 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
- May 121 year in 10 after May 25; 9 in 10 after April 29
- First autumn frost, half of years before
- September 281 year in 10 before September 14; 9 in 10 before October 10
NOAA puts the median frost-free season at 139 days, and the season without a hard freeze (28°F) at 156 days.
A hard freeze (28°F) comes after May 2 in half of springs and before October 5 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Byron in zone 4b in ZIP code 55920, the nearest ZIP area.
Frost dates for every NOAA station in Minnesota · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00211174; 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 in Byron?
In a normal year in Byron, 8 days a year reach 90°F, 176 nights fall to 32°F or colder and 111 days bring measurable precipitation.
- Days at 90°F or more
- 8a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 176a normal year
- Days that stay below freezing
- 73high of 32°F or less
- Days with 0.01 inch of precipitation
- 111a normal year
- Days with 1 inch of snow or more
- 12a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00211174.
How sunny is Byron?
Over a year 73% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Byron, 3.9 kWh per square metre a day. July is the sunniest month (81%) and December the cloudiest (61%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 71% | 1.8 |
| February | 77% | 2.9 |
| March | 72% | 3.8 |
| April | 68% | 4.7 |
| May | 69% | 5.4 |
| June | 74% | 6.0 |
| July | 81% | 6.3 |
| August | 78% | 5.3 |
| September | 75% | 4.1 |
| October | 68% | 2.7 |
| November | 65% | 1.7 |
| December | 61% | 1.3 |
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 Byron need?
A normal year in Byron brings 8,328 heating degree days, 55% more than the median U.S. place (5,373), and 442 cooling degree days, 51% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,272 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,610 | 0 |
| February | 1,351 | 0 |
| March | 1,087 | 0 |
| April | 653 | 1 |
| May | 309 | 21 |
| June | 66 | 101 |
| July | 20 | 164 |
| August | 43 | 111 |
| September | 209 | 41 |
| October | 597 | 3 |
| November | 980 | 0 |
| December | 1,404 | 0 |
| Year (annual) | 8,328 | 442 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00211174. 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.
How does Byron's climate compare?
Byron is warmer than 64 of the other 128 places with their own NOAA record in Minnesota, and wetter than 112. Across the 7,247 U.S. stations with normals, its annual mean of 43.3°F is warmer than 13%.
In the Köppen classification computed from these normals, Byron is Dfb: continental, no dry season, warm 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 Byron share this climate record?
6 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.
- Kasson, MN7,207 people · 7 mi SW
- Dodge Center, MN2,939 people · 11 mi W
- Oronoco, MN2,040 people · 7 mi NE
- Hayfield, MN1,361 people · 17 mi SW
- Mantorville, MN1,110 people · 6 mi W
- West Concord, MN842 people · 14 mi W
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 Byron's climate
What is the coldest month in Byron?
January, with a normal high of 23°F and a normal low of 4°F. The warmest is July (81°F by day, 58°F at night).
Does it snow in Byron?
Yes: 44 inches in a normal year, falling on 26 days with 0.1 inch or more, the most in December (12.5 inches).
What is the rainiest month in Byron?
June, with 5.27 in of precipitation in a normal year; the driest is January with 1.02 in.
What plant hardiness zone is Byron in?
The USDA's 2023 map puts Byron in zone 4b in ZIP code 55920, the nearest ZIP area.
How late can frost come in Byron?
In half of years the last 32°F night comes after May 12; in one year in ten it comes after May 25. Waiting until May 25 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Minnesota climateThe statewide normals and every place in the state
- Zumbrota, MN14 miles from this station, 44.0°F a year
- Rochester, MN15 miles from this station, 44.8°F a year
- Theilman (1 mi SSW), MN25 miles from this station, 45.0°F a year
- Grand Meadow, MN27 miles from this station, 42.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made