Defiance, Ohio climate: Normal weather by month, frost dates and records
Defiance's normal year runs from 18°F January nights to 84°F July afternoons, with 33.0 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.0°C, January lows of −8°C, July highs of 29°C, 837 mm of precipitation a year.
- NOAA stationDefiance Mem Airport
- Station IDUSW00004851
- Location41.34°N 84.43°W
- Elevation708 ft (216 m)
- From the center5 miles
- Population17,180
On October 23, the normal high in Defiance is 60°F and the normal low 40°F, and the chance of measurable rain or snow is 32%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Defiance.
- Jan 32° 18°
- Feb 36° 20°
- Mar 47° 28°
- Apr 60° 39°
- May 71° 49°
- Jun 80° 59°
- Jul 84° 62°
- Aug 82° 60°
- Sep 75° 53°
- Oct 63° 42°
- Nov 49° 33°
- Dec 37° 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 in Defiance each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 18°F. The most precipitation falls in May (3.89 in), the least in February (1.65 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 32°F | 18°F | 25.2°F | 1.94 | 10 | <1 | 27 | 9 h 30 min |
| February | 36°F | 20°F | 27.8°F | 1.65 | 10 | <1 | 25 | 10 h 40 min |
| March | 47°F | 28°F | 37.4°F | 2.26 | 10 | <1 | 21 | 11 h 50 min |
| April | 60°F | 39°F | 49.2°F | 3.48 | 12 | <1 | 7 | 13 h 20 min |
| May | 71°F | 49°F | 60.0°F | 3.89 | 13 | 1 | 1 | 14 h 30 min |
| June | 80°F | 59°F | 69.5°F | 3.38 | 11 | 4 | <1 | 15 h 10 min |
| July | 84°F | 62°F | 72.9°F | 3.63 | 10 | 7 | <1 | 14 h 50 min |
| August | 82°F | 60°F | 70.8°F | 3.37 | 11 | 3 | <1 | 13 h 50 min |
| September | 75°F | 53°F | 63.9°F | 2.67 | 10 | 2 | <1 | 12 h 30 min |
| October | 63°F | 42°F | 52.3°F | 2.32 | 11 | <1 | 4 | 11 h 10 min |
| November | 49°F | 33°F | 40.6°F | 2.48 | 9 | <1 | 15 | 9 h 50 min |
| December | 37°F | 24°F | 30.3°F | 1.88 | 10 | <1 | 24 | 9 h 10 min |
| Year (annual) | 60°F | 41°F | 50.0°F | 32.95 | 127 | 16 | 124 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 0°C | −8°C | −3.8°C | 49 mm |
| February | 2°C | −7°C | −2.3°C | 42 mm |
| March | 8°C | −2°C | 3.0°C | 57 mm |
| April | 16°C | 4°C | 9.6°C | 88 mm |
| May | 22°C | 10°C | 15.6°C | 99 mm |
| June | 27°C | 15°C | 20.8°C | 86 mm |
| July | 29°C | 17°C | 22.7°C | 92 mm |
| August | 28°C | 16°C | 21.6°C | 86 mm |
| September | 24°C | 11°C | 17.7°C | 68 mm |
| October | 17°C | 5°C | 11.3°C | 59 mm |
| November | 9°C | 0°C | 4.8°C | 63 mm |
| December | 3°C | −5°C | −0.9°C | 48 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. Defiance's own co-op station Defiance station does: 24 inches of snow in a normal year (see the other stations below).
Source: NOAA NCEI 1991-2020 monthly normals, station USW00004851; 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 Defiance?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, July 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 USW00004851.
When is the last frost in Defiance?
In Defiance, the last spring frost (32°F) comes after April 28 in half of years and after May 14 in one year in ten; the first autumn frost comes before October 17 in half of years and before October 1 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 281 year in 10 after May 14; 9 in 10 after April 13
- First autumn frost, half of years before
- October 171 year in 10 before October 1; 9 in 10 before November 1
NOAA puts the median frost-free season at 170 days, and the season without a hard freeze (28°F) at 195 days.
A hard freeze (28°F) comes after April 15 in half of springs and before October 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Defiance in zone 6a in ZIP code 43512, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Defiance's NOAA station is in zone 6a: the coldest night of a typical year reaches −7°F (20 complete years).
Frost dates for every NOAA station in Ohio · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00004851; 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.
How hot and how cold does it get in Defiance?
In a normal year in Defiance, 16 days a year reach 90°F, 124 nights fall to 32°F or colder and 127 days bring measurable precipitation.
- Days at 90°F or more
- 16a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 124a normal year
- Days that stay below freezing
- 40high of 32°F or less
- Days with 0.01 inch of precipitation
- 127a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USW00004851.
How sunny is Defiance?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Defiance, 3.9 kWh per square metre a day. July is the sunniest month (81%) and December the cloudiest (56%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 58% | 1.6 |
| February | 63% | 2.5 |
| March | 65% | 3.5 |
| April | 69% | 4.7 |
| May | 71% | 5.5 |
| June | 77% | 6.2 |
| July | 81% | 6.2 |
| August | 80% | 5.4 |
| September | 78% | 4.4 |
| October | 69% | 2.9 |
| November | 65% | 1.9 |
| December | 56% | 1.4 |
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 Defiance need?
A normal year in Defiance brings 6,179 heating degree days, 15% more than the median U.S. place (5,373), and 747 cooling degree days, 18% fewer 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 2,994 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,234 | 0 |
| February | 1,042 | 0 |
| March | 855 | 1 |
| April | 479 | 5 |
| May | 202 | 47 |
| June | 32 | 166 |
| July | 4 | 250 |
| August | 11 | 192 |
| September | 108 | 75 |
| October | 404 | 11 |
| November | 732 | 0 |
| December | 1,076 | 0 |
| Year (annual) | 6,179 | 747 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00004851. 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 Defiance been warmer than normal lately?
2025 averaged 51.3°F, 1.3°F above the 1991-2020 normal of 50.0°F. 4 of the 4 complete years since 2022 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2022 | 51.5°F | +1.5°F | 26.91 |
| 2023 | 52.8°F | +2.8°F | 28.30 |
| 2024 | 54.1°F | +4.1°F | 33.44 |
| 2025 | 51.3°F | +1.3°F | 27.15 |
Source: observed years: ACIS, station USW00004851. A year counts only with all twelve months complete.
How does Defiance's climate compare?
Defiance is warmer than 15 of the other 98 places with their own NOAA record in Ohio, and wetter than 0. Across the 7,247 U.S. stations with normals, its annual mean of 50.0°F is warmer than 40%.
In the Köppen classification computed from these normals, Defiance is Dfa: continental, 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 Defiance share this climate record?
2 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.
- Sherwood, OH822 people · 7 mi SW
- Brunersburg, OH364 people · 3 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 Defiance's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Defiance. This page uses Defiance Mem Airport; the other differs by site and elevation:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Defiance station USC00332098 | 1 mi W | 700 ft | 50.4°F | 18°F | 85°F | 37.7 | 24 | April 22 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Defiance's climate
What is the coldest month in Defiance?
January, with a normal high of 32°F and a normal low of 18°F. The warmest is July (84°F by day, 62°F at night).
Does it snow in Defiance?
Yes. NOAA publishes no 1991-2020 snowfall normal for Defiance's NOAA station; Defiance's own co-op station Defiance station records 24 inches of snow in a normal year.
What is the rainiest month in Defiance?
May, with 3.89 in of precipitation in a normal year; the driest is February with 1.65 in.
What plant hardiness zone is Defiance in?
The USDA's 2023 map puts Defiance in zone 6a in ZIP code 43512, the nearest ZIP area. By the same method at Defiance's NOAA station, the coldest night of a typical year reaches −7°F (20 years, 1991-2020): zone 6a.
How late can frost come in Defiance?
In half of years the last 32°F night comes after April 28; in one year in ten it comes after May 14. Waiting until May 14 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Ohio climateThe statewide normals and every place in the state
- Bryan, OH10 miles from this station, 49.7°F a year
- Napoleon, OH17 miles from this station, 50.2°F a year
- Paulding, OH17 miles from this station, 50.3°F a year
- Hicksville, OH17 miles from this station, 50.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made