Bristol, Wisconsin Weather
Fireflies rise from the lawn. Day 76 of spring. Read this microseason across nine climate regions →
Bristol weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Overcast——80°46°—
- ThursdayJun 4Overcast——86°57°+6°
- FridayJun 5Light Showers65%0.29″77°66°-9°
- SaturdayJun 6Showers54%1.1″71°60°-6°
- SundayJun 7Foggy——76°54°+5°
- MondayJun 8Light Drizzle13%—75°60°-1°
- TuesdayJun 9Light Drizzle19%—79°67°+4°
PM2.5 at 9.1 µg/m³, PM10 at 9.7 µg/m³ — typical background levels with no transport signature. AQI flat over the last 6 hours (within ±3 points).
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 43 now. With UV 7.2 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 29 by mid-afternoon.
- Present
- AQI 43
- UV peak
- 7.2 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 29
PM × Wind × Precip
PM2.5 at 9.1 µg/m³, PM10 at 9.7 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.94
- 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).
The higher the clouds, the finer the weather.
- Moonrise
- 3:53 AM
- Moonset
- 12:40 PM
- In sign
- ♑︎ Capricorn
Fireflies rise from the lawn
Bristol at a glance
- Today vs. normal: 7°F above the seasonal normal for this latitude
- Last frost: May 1 (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 3, 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 — Bristol
SPC has placed Bristol 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 | — | — |
| May | lettuce, peas, spinach, radishes | lettuce, peas, radishes |
| June | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | tomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | — | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
Bristol's warmest month is July (~73°F mean) and its coldest is January (~22°F). Rainfall peaks in May (4.4 inches) and bottoms out in February (1.9 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 22° | 2.1″ | 6 |
| February | 26° | 1.9″ | 4 |
| March | 36° | 2.6″ | 5 |
| April | 47° | 4.1″ | 7 |
| May | 58° | 4.4″ | 7 |
| June | 68° | 4.2″ | 6 |
| July | 73° | 3.9″ | 6 |
| August | 71° | 3.3″ | 6 |
| September | 64° | 3.4″ | 5 |
| October | 52° | 3.0″ | 5 |
| November | 39° | 2.5″ | 6 |
| December | 28° | 2.3″ | 4 |
Regional context
Bristol sits within a warm-summer humid continental climate region — a cohort that shares similar temperature ranges, seasonal patterns, and growing conditions across nearby cities.
Similar climates: Milwaukee, WI, Madison, WI, Appleton, WI, Green Bay, WI, Racine, WI.
Frequently asked
- When does it freeze in Bristol?
- Bristol's last spring frost typically falls around mid-May, and the first fall frost arrives around mid-October.
- What is the rainy season in Bristol?
- May is the wettest month with about 4.4 inches of rain on average; the city receives roughly 38 inches annually.
- What is the warmest month in Bristol?
- July is typically warmest, averaging about 73°F.
- What is the coldest month in Bristol?
- January is typically coldest, averaging about 22°F.
- When can I start a vegetable garden in Bristol?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-May); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Bristol get?
- Bristol averages about 67 rainy days per year.
- What hardiness zone is Bristol?
- Bristol'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
Bristol, Wisconsin sits in a warm-summer humid continental climate zone. January means hover near 22°F while July averages 73°F — a 51°F seasonal swing.
Across the year, Bristol receives about 38 inches of precipitation spread over roughly 67 rainy days.
The rhythm of the year is set by latitude (42.5°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.