Napoleon, Ohio climate: Normal weather by month, frost dates and records
Napoleon's normal year runs from 17°F January nights to 84°F July afternoons, with 37.3 inches of precipitation and 25 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.1°C, January lows of −8°C, July highs of 29°C, 948 mm of precipitation a year.
- NOAA stationNapoleon
- Station IDUSC00335669
- Location41.39°N 84.11°W
- Elevation682 ft (208 m)
- From the centerunder 1 mile
- Population8,724
On October 23, the normal high in Napoleon is 61°F and the normal low 40°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 Napoleon.
- Jan 33° 17°
- Feb 36° 19°
- Mar 46° 28°
- Apr 60° 37°
- May 72° 50°
- Jun 81° 60°
- Jul 84° 63°
- Aug 83° 60°
- Sep 76° 53°
- Oct 64° 42°
- Nov 49° 32°
- 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 Napoleon each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 17°F. The most precipitation falls in May (4.02 in), the least in February (2.25 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 33°F | 17°F | 25.1°F | 2.53 | 9.5 | 11 | <1 | 28 | 9 h 30 min |
| February | 36°F | 19°F | 27.2°F | 2.25 | 6.0 | 9 | <1 | 26 | 10 h 40 min |
| March | 46°F | 28°F | 36.9°F | 2.60 | 4.3 | 10 | <1 | 23 | 11 h 50 min |
| April | 60°F | 37°F | 48.4°F | 3.65 | 0.0 | 12 | <1 | 9 | 13 h 20 min |
| May | 72°F | 50°F | 60.7°F | 4.02 | 0.0 | 11 | 1 | 1 | 14 h 30 min |
| June | 81°F | 60°F | 70.3°F | 3.67 | 0.0 | 10 | 4 | <1 | 15 h 10 min |
| July | 84°F | 63°F | 73.5°F | 3.45 | 0.0 | 10 | 4 | <1 | 14 h 50 min |
| August | 83°F | 60°F | 71.7°F | 3.71 | 0.0 | 8 | 5 | <1 | 13 h 50 min |
| September | 76°F | 53°F | 64.6°F | 3.31 | 0.0 | 8 | 2 | 1 | 12 h 30 min |
| October | 64°F | 42°F | 53.0°F | 2.74 | 0.0 | 9 | <1 | 4 | 11 h 10 min |
| November | 49°F | 32°F | 40.6°F | 2.86 | 0.4 | 10 | <1 | 16 | 9 h 50 min |
| December | 37°F | 24°F | 30.6°F | 2.53 | 4.5 | 10 | <1 | 26 | 9 h 10 min |
| Year (annual) | 60°F | 40°F | 50.2°F | 37.32 | 24.7 | 119 | 15 | 134 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −8°C | −3.8°C | 64 mm | 24 cm |
| February | 2°C | −7°C | −2.7°C | 57 mm | 15 cm |
| March | 8°C | −2°C | 2.7°C | 66 mm | 11 cm |
| April | 15°C | 3°C | 9.1°C | 93 mm | 0 cm |
| May | 22°C | 10°C | 15.9°C | 102 mm | 0 cm |
| June | 27°C | 15°C | 21.3°C | 93 mm | 0 cm |
| July | 29°C | 17°C | 23.1°C | 88 mm | 0 cm |
| August | 28°C | 16°C | 22.1°C | 94 mm | 0 cm |
| September | 25°C | 12°C | 18.1°C | 84 mm | 0 cm |
| October | 18°C | 6°C | 11.7°C | 70 mm | 0 cm |
| November | 10°C | 0°C | 4.8°C | 73 mm | 1 cm |
| December | 3°C | −5°C | −0.8°C | 64 mm | 11 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00335669; 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 Napoleon?
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 (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 USC00335669.
When is the last frost in Napoleon?
In Napoleon, the last spring frost (32°F) comes after April 24 in half of years and after May 7 in one year in ten; the first autumn frost comes before October 21 in half of years and before October 5 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 7; 9 in 10 after April 13
- First autumn frost, half of years before
- October 211 year in 10 before October 5; 9 in 10 before November 3
NOAA puts the median frost-free season at 179 days, and the season without a hard freeze (28°F) at 201 days.
A hard freeze (28°F) comes after April 14 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Napoleon in zone 6a in ZIP code 43545, the nearest ZIP area.
Frost dates for every NOAA station in Ohio · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00335669; 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 Napoleon?
In a normal year in Napoleon, 15 days a year reach 90°F, 134 nights fall to 32°F or colder and 119 days bring measurable precipitation.
- Days at 90°F or more
- 15a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 134a normal year
- Days that stay below freezing
- 47high of 32°F or less
- Days with 0.01 inch of precipitation
- 119a normal year
- Days with 1 inch of snow or more
- 9a normal year
The highest temperature in this station's record (since 1893) is 111°F, on August 6, 1947; the lowest is −24°F, on January 21, 1984.
The wettest calendar year on that record is 1950, with 53.33 in; the snowiest season is 1977–78, with 64.8 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00335669; records: ACIS (NOAA Regional Climate Centers), station USC00335669. Records use complete months only; a month missing more than three days is left out.
How sunny is Napoleon?
Over a year 72% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Napoleon, 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 Napoleon need?
A normal year in Napoleon brings 6,183 heating degree days, 15% more than the median U.S. place (5,373), and 827 cooling degree days, 9% 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 3,090 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,237 | 0 |
| February | 1,060 | 0 |
| March | 873 | 0 |
| April | 504 | 6 |
| May | 187 | 54 |
| June | 29 | 188 |
| July | 2 | 266 |
| August | 11 | 218 |
| September | 98 | 84 |
| October | 383 | 11 |
| November | 734 | 0 |
| December | 1,066 | 0 |
| Year (annual) | 6,183 | 827 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00335669. 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 Napoleon's climate compare?
Napoleon is warmer than 20 of the other 98 places with their own NOAA record in Ohio, and wetter than 12. Across the 7,247 U.S. stations with normals, its annual mean of 50.2°F is warmer than 41%.
In the Köppen classification computed from these normals, Napoleon 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 Napoleon share this climate record?
8 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.
- Liberty Center, OH1,090 people · 7 mi NE
- Holgate, OH1,046 people · 10 mi S
- Grand Rapids, OH932 people · 13 mi E
- McClure, OH690 people · 9 mi E
- Hamler, OH600 people · 12 mi S
- Malinta, OH228 people · 7 mi SE
- Florida, OH216 people · 7 mi SW
- New Bavaria, OH86 people · 13 mi S
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 Napoleon's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Napoleon. This page uses Napoleon; the other differs by site and elevation:
| Station | From the center | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Napoleon (1 mi SW) USC00335667 | 2 mi SW | 670 ft | 50.7°F | 18°F | 85°F | 36.6 | – | April 23 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Napoleon's climate
What is the coldest month in Napoleon?
January, with a normal high of 33°F and a normal low of 17°F. The warmest is July (84°F by day, 63°F at night).
Does it snow in Napoleon?
Yes: 25 inches in a normal year, falling on 16 days with 0.1 inch or more, the most in January (9.5 inches).
What is the rainiest month in Napoleon?
May, with 4.02 in of precipitation in a normal year; the driest is February with 2.25 in.
What plant hardiness zone is Napoleon in?
The USDA's 2023 map puts Napoleon in zone 6a in ZIP code 43545, the nearest ZIP area.
How late can frost come in Napoleon?
In half of years the last 32°F night comes after April 24; in one year in ten it comes after May 7. Waiting until May 7 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Ohio climateThe statewide normals and every place in the state
- Wauseon, OH9 miles from this station, 49.2°F a year
- Defiance, OH17 miles from this station, 50.0°F a year
- Toledo, OH21 miles from this station, 52.2°F a year
- Hoytville, OH22 miles from this station, 50.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made