Blue Ash, Ohio Weather
Cicadas claim the scorching afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Blue Ash weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Light Drizzle20%0.01″94°74°—
- SundayJul 5Drizzle36%0.04″89°72°-5°
- MondayJul 6Light Drizzle49%—81°69°-8°
- TuesdayJul 7Overcast14%—82°63°+1°
- WednesdayJul 8Overcast——86°64°+4°
- ThursdayJul 9Light Drizzle37%—86°67°0°
- FridayJul 10Light Drizzle57%—80°70°-6°
AQI 57 (Moderate), driven by Ozone. Ozone at AQI 138 now. With UV 7.6 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 139 around 1 PM.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 10 PM.
What's driving it
Ozone × UV × Sky
Ozone at AQI 138 now. With UV 7.6 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 139 around 1 PM.
- Present
- AQI 138
- UV peak
- 7.6 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 139
PM × Wind × Precip
PM2.5 at 13.2 µg/m³, PM10 at 14.8 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.89
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- background
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).








































If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 11:31 PM
- Moonset
- 10:43 AM
- In sign
- ♓︎ Pisces
Cicadas claim the scorching afternoon
Blue Ash at a glance
- Today vs. normal: 19°F above the seasonal normal for this latitude
- Last frost: April 11 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
16-Day Forecast — Blue Ash
- Sat94°74°20%
- Sun89°72°36%
- Mon81°69°49%
- Tue82°63°14%
- Wed86°64°8%
- Thu86°67°37%
- Fri80°70°57%
- Sat84°68°45%
- Sun77°62°18%
- Mon70°56°14%
- Tue75°61°15%
- Wed83°62°23%
- Thu86°66°23%
- Fri86°69°17%
- Sat86°67°35%
- Sun89°70°30%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 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.
SPC Convective Outlook
Storm Prediction Center — Blue Ash
SPC has placed Blue Ash in the Marginal Risk category for severe thunderstorms today.
- TODAYMRGLMarginal Risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3TSTMGeneral Thunderstorms
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.
Microseason · July 1–5
Cicadas claim the scorching afternoon
Dog-day cicadas emerge in waves, their rasp dominating every sunny hour; heat peaks above 90 degrees daily.
Day 185 of 365 · Wedge 37 of 72
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
The year in Blue Ash tops out in July (~78°F) and dips lowest in January (~30°F), with May wettest at 4.4 inches and September driest at 2.3 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 30° | 3.0″ | 16 |
| February | 34° | 3.0″ | 15 |
| March | 43° | 4.1″ | 17 |
| April | 55° | 4.2″ | 18 |
| May | 63° | 4.4″ | 18 |
| June | 73° | 3.6″ | 16 |
| July | 78° | 3.4″ | 17 |
| August | 77° | 3.0″ | 16 |
| September | 70° | 2.3″ | 13 |
| October | 58° | 2.6″ | 11 |
| November | 44° | 3.1″ | 14 |
| December | 34° | 3.9″ | 16 |
Regional context
Per NOAA NCEI 1991-2020 normals, Blue Ash runs from a 30°F January mean to 78°F in July, a 47°F seasonal spread, with near 40.6 inches of precipitation across about 187 wet days.
Blue Ash's precipitation spreads evenly: May peaks at 4.4 inches on 18.2 wet days, while September holds 2.3 inches over 13.0 — no month dominates Blue Ash's rain calendar. That lines Blue Ash up with places like Montgomery, OH, Rossmoyne, OH and Evendale, OH, fed by overlapping storm tracks.
Blue Ash reaches its last hard frost near mid-April; that is the cue for peas, lettuce, spinach, and radishes. Tomatoes and peppers do best set out two weeks later in Blue Ash, once nights clear the mid-40s°F. The season ends by mid-November in Blue Ash, once hard frosts set back in. Blue Ash's low ground holds frost later into spring than Blue Ash's benches, which run 3-5 days ahead.
Similar climates: Montgomery, OH, Rossmoyne, OH, Evendale, OH, Dillonvale, OH, Brecon, OH.
Frequently asked
- When does it freeze in Blue Ash?
- Blue Ash's last spring frost lands near mid-April, and in Blue Ash the first fall frost follows around mid-November.
- What is the rainy season in Blue Ash?
- Blue Ash sees its heaviest rain in May (around 4.4 inches), part of roughly 41 inches a year.
- What is the warmest month in Blue Ash?
- On average July tops the year in Blue Ash at about 78°F.
- What is the coldest month in Blue Ash?
- The coldest stretch in Blue Ash falls in January, around 30°F on average.
- When can I start a vegetable garden in Blue Ash?
- In Blue Ash, sow peas and hardy greens around mid-April; Blue Ash's tomatoes and peppers wait two weeks more.
- How many rainy days does Blue Ash get?
- Blue Ash averages about 187 days with measurable rain or snow each year.
- What hardiness zone is Blue Ash?
- Because Blue Ash bottoms near 30°F in January, that winter low sets Blue Ash's USDA zone — verify by ZIP.
- What is the 10-day forecast for Blue Ash?
- Blue Ash's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Blue Ash?
- See this week's day-by-day rain chances for Blue Ash in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Blue Ash?
- Current conditions for Blue Ash and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Blue Ash forecast updated?
- The Blue Ash forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Blue Ash?
- Today's sunrise and sunset times for Blue Ash are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Blue Ash?
- The next few days in Blue Ash's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
In Blue Ash, Ohio, the humid subtropical climate runs from about 30°F in January to 78°F in July, a 48°F seasonal range.
Rain and snow bring Blue Ash roughly 41 inches a year across approximately 187 measurable-precipitation days.
Blue Ash's 48°F range, set by its 39.2°N position, drives frost timing and what thrives in Blue Ash.
ZIP codes in Blue Ash
- 45241
- 45242
- 45236