Mount Vernon, Ohio Weather
Fireflies pulse through the magnolias. Day 77 of spring. Read this microseason across nine climate regions →
Mount Vernon weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Clear——78°47°—
- ThursdayJun 4Overcast——82°57°+4°
- FridayJun 5Overcast——79°59°-3°
- SaturdayJun 6Light Showers80%—77°61°-2°
- SundayJun 7Light Drizzle80%—82°64°+5°
- MondayJun 8Light Drizzle——83°60°+1°
- TuesdayJun 9Light Drizzle13%—80°65°-3°
Ozone at AQI 34 now. AQI up 7 over the last 6 hours (gradual rise). With UV 0.0 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 6 by mid-afternoon.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 34 now. With UV 0.0 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 6 by mid-afternoon.
- Present
- AQI 34
- UV peak
- 0.0 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 6
PM × Wind × Precip
PM2.5 at 4.7 µg/m³ (AQI 26) with a 0.85 fine-to-coarse ratio and 4 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.85
- Wind
- calm
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 3:59 AM
- Moonset
- 1:29 PM
- In sign
- ♑︎ Capricorn
Fireflies pulse through the magnolias
Mount Vernon at a glance
- Today vs. normal: 8°F below the seasonal normal for this latitude
- Last frost: April 18 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 4, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
Mount Vernon's warmest month is July (~71°F mean) and its coldest is January (~26°F). Rainfall peaks in June (4.9 inches) and bottoms out in February (2.5 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 26° | 3.1″ | 7 |
| February | 28° | 2.5″ | 6 |
| March | 37° | 3.3″ | 8 |
| April | 48° | 4.0″ | 9 |
| May | 58° | 4.7″ | 9 |
| June | 67° | 4.9″ | 9 |
| July | 71° | 4.2″ | 8 |
| August | 69° | 3.4″ | 6 |
| September | 62° | 3.2″ | 6 |
| October | 51° | 2.9″ | 6 |
| November | 40° | 3.0″ | 7 |
| December | 31° | 3.2″ | 7 |
Regional context
Mount Vernon's baseline climate, derived from NOAA NCEI 1991-2020 normals at the nearest reporting station, swings from a January mean of 26°F to a July mean of 71°F — a 45°F seasonal arc typical of the mid-latitude bands. Annual precipitation runs about 42.4 inches spread across roughly 87 days with measurable rain or snow each year.
Rainfall stays relatively even across the calendar: June tops out at 4.9 inches across 8.6 days with measurable rain, and February settles around 2.5 inches across 6.0 rainy days — a comparatively narrow seasonal range. The balanced distribution lines Mount Vernon up with places like South Mount Vernon, OH, Gambier, OH and Fredericktown, OH, all of which run on overlapping storm tracks rather than a single seasonal moisture source.
The frost-sensitive growing window opens around mid-April, when overnight lows reliably clear freezing for cool-season crops like kale, peas, spinach, and parsnips. Warm-soil crops — tomatoes, peppers, eggplant — wait until soil temperatures reach the mid-50s°F, usually two weeks past the last-frost date. The window closes around mid-November, when overnight lows resume dipping below freezing and frost-tender plants need protection or harvest. These dates represent 30-year central tendencies; actual year-to-year variation can shift either bookend by 7-14 days, and local microclimate features within Mount Vernon — cold-air drainage on calm clear nights, slope aspect, distance from any nearby lake or river — can push the practical frost window earlier or later than the regional average.
Similar climates: South Mount Vernon, OH, Gambier, OH, Fredericktown, OH, Apple Valley, OH, Howard, OH.
Frequently asked
- When does it freeze in Mount Vernon?
- Mount Vernon's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Mount Vernon?
- June is the wettest month with about 4.9 inches of rain on average; the city receives roughly 42 inches annually.
- What is the warmest month in Mount Vernon?
- July is typically warmest, averaging about 71°F.
- What is the coldest month in Mount Vernon?
- January is typically coldest, averaging about 26°F.
- When can I start a vegetable garden in Mount Vernon?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-April); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Mount Vernon get?
- Mount Vernon averages about 87 rainy days per year.
- What hardiness zone is Mount Vernon?
- Mount Vernon's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Mount Vernon, Ohio sits in a humid subtropical climate zone. January means hover near 26°F while July averages 71°F — a 45°F seasonal swing.
Across the year, Mount Vernon receives about 42 inches of precipitation spread over roughly 87 rainy days.
The rhythm of the year is set by latitude (40.4°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.