Mariemont, Ohio Weather
Fireflies pulse through the magnolias. Day 78 of spring. Read this microseason across nine climate regions →
Mariemont weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——84°54°—
- FridayJun 5Overcast——87°63°+3°
- SaturdayJun 6Overcast30%—90°66°+3°
- SundayJun 7Drizzle47%—82°68°-8°
- MondayJun 8Light Drizzle24%—79°64°-3°
- TuesdayJun 9Heavy Drizzle28%0.02″74°67°-5°
- WednesdayJun 10Light Showers31%0.01″79°69°+5°
AQI 85 (Moderate), driven by Ozone. AQI up 22 in the last 6 hours — air quality is degrading. Ozone at AQI 39 now. With UV 0.0 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 7 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 39 now. With UV 0.0 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 7 by mid-afternoon.
- Present
- AQI 39
- UV peak
- 0.0 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 7
PM × Wind × Precip
PM2.5 at 6.8 µg/m³ (AQI 38) with a 0.89 fine-to-coarse ratio and 4 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.89
- 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).
The higher the clouds, the finer the weather.
- Moonrise
- 4:36 AM
- Moonset
- 2:46 PM
- In sign
- ♒︎ Aquarius
Fireflies pulse through the magnolias
Mariemont at a glance
- Today vs. normal: 4°F below the seasonal normal for this latitude
- Last frost: April 11 (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 5, 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.
SPC Convective Outlook
Storm Prediction Center — Mariemont
SPC has placed Mariemont in the Marginal Risk category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3MRGLMarginal Risk
Isolated severe storms possible. Limited threat for hail or damaging wind.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
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
Mariemont's warmest month is July (~76°F mean) and its coldest is January (~32°F). Rainfall peaks in May (4.7 inches) and bottoms out in February (2.8 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 32° | 2.9″ | 6 |
| February | 35° | 2.8″ | 6 |
| March | 44° | 3.9″ | 8 |
| April | 55° | 4.4″ | 8 |
| May | 64° | 4.7″ | 9 |
| June | 72° | 4.6″ | 8 |
| July | 76° | 4.4″ | 7 |
| August | 75° | 3.4″ | 6 |
| September | 68° | 3.1″ | 5 |
| October | 56° | 3.0″ | 6 |
| November | 45° | 2.9″ | 6 |
| December | 36° | 3.3″ | 6 |
Regional context
Mariemont sits within a humid subtropical climate region — a cohort that shares similar temperature ranges, seasonal patterns, and growing conditions across nearby cities.
Similar climates: Cincinnati, OH, Columbus, OH, Dayton, OH, Middletown, OH, Newark, OH.
Frequently asked
- When does it freeze in Mariemont?
- Mariemont's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Mariemont?
- May is the wettest month with about 4.7 inches of rain on average; the city receives roughly 43 inches annually.
- What is the warmest month in Mariemont?
- July is typically warmest, averaging about 76°F.
- What is the coldest month in Mariemont?
- January is typically coldest, averaging about 32°F.
- When can I start a vegetable garden in Mariemont?
- 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 Mariemont get?
- Mariemont averages about 80 rainy days per year.
- What hardiness zone is Mariemont?
- Mariemont'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
Mariemont, Ohio sits in a humid subtropical climate zone. January means hover near 32°F while July averages 76°F — a 44°F seasonal swing.
Across the year, Mariemont receives about 43 inches of precipitation spread over roughly 80 rainy days.
The rhythm of the year is set by latitude (39.1°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.