Thornhill, Kentucky Weather
Fireflies pulse through the magnolias. Day 78 of spring. Read this microseason across nine climate regions →
Thornhill weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Mostly Clear——85°59°—
- FridayJun 5Overcast——86°66°+1°
- SaturdayJun 6Overcast——83°68°-3°
- SundayJun 7Light Showers26%0.31″73°69°-10°
- MondayJun 8Showers43%0.17″77°67°+4°
- TuesdayJun 9Showers40%—78°68°+1°
- WednesdayJun 10Showers36%0.44″85°70°+7°
Ozone at AQI 48. AQI up 32 in the last 6 hours — air quality is degrading. Overcast through the UV peak window (cloud cover ~76%) — afternoon ozone should stay flat.
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 48. Overcast through the UV peak window (cloud cover ~76%) — afternoon ozone should stay flat.
- Present
- AQI 48
- UV peak
- 0.1 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 6
PM × Wind × Precip
PM2.5 at 5.4 µg/m³ (AQI 30) with a 0.84 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.84
- Wind
- light
- 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
- 4:39 AM
- Moonset
- 2:53 PM
- In sign
- ♒︎ Aquarius
Fireflies pulse through the magnolias
Thornhill at a glance
- Today vs. normal: 79°F — typical for the season
- Last frost: April 6 (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 — Thornhill
SPC has placed Thornhill in the General Thunderstorms category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
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
Thornhill's warmest month is July (~78°F mean) and its coldest is January (~34°F). Rainfall peaks in May (5.8 inches) and bottoms out in August (3.3 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 34° | 3.8″ | 7 |
| February | 38° | 3.7″ | 7 |
| March | 47° | 5.1″ | 8 |
| April | 57° | 5.3″ | 9 |
| May | 66° | 5.8″ | 9 |
| June | 74° | 4.9″ | 8 |
| July | 78° | 4.7″ | 8 |
| August | 77° | 3.3″ | 6 |
| September | 70° | 3.8″ | 5 |
| October | 59° | 4.2″ | 6 |
| November | 47° | 3.9″ | 6 |
| December | 38° | 4.6″ | 8 |
Frequently asked
- When does it freeze in Thornhill?
- Thornhill's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Thornhill?
- May is the wettest month with about 5.8 inches of rain on average; the city receives roughly 53 inches annually.
- What is the warmest month in Thornhill?
- July is typically warmest, averaging about 78°F.
- What is the coldest month in Thornhill?
- January is typically coldest, averaging about 34°F.
- When can I start a vegetable garden in Thornhill?
- 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 Thornhill get?
- Thornhill averages about 85 rainy days per year.
- What hardiness zone is Thornhill?
- Thornhill'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
Thornhill, Kentucky sits in a humid subtropical climate zone. January means hover near 34°F while July averages 78°F — a 43°F seasonal swing.
Across the year, Thornhill receives about 53 inches of precipitation spread over roughly 85 rainy days.
The rhythm of the year is set by latitude (38.3°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.