St. Helen, Michigan Weather
Day 93 of summer. Read today’s microseason across nine climate regions →
St. Helen weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 10:22 AM EDT · Open-Meteo
- TodaySep 21Overcast——55°45°—
- TuesdaySep 22Overcast——58°43°+3°
- WednesdaySep 23Overcast——66°44°+8°
- ThursdaySep 24Overcast——69°46°+3°
- FridaySep 25Overcast——71°49°+2°
- SaturdaySep 26Overcast——72°46°+1°
- SundaySep 27Light Drizzle—0.04″60°53°-12°
Air quality now AQI 35 · Good
AQI 35 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 6.9 µg/m³, PM10 at 7.7 µg/m³ — typical background levels with no transport signature.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 6.9 µg/m³, PM10 at 7.7 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.90
- Wind
- breezy
- 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).
September dries up ditches or breaks down bridges.
- Moonrise
- 5:24 PM
- Moonset
- 1:42 AM
- In sign
- ♑︎ Capricorn
St. Helen at a glance
- Today vs. normal: Today averages 50°F (high 55°F, low 45°F), 7°F below the 57°F normal for Sep 21
- Last frost: May 15 (1991–2020 median, NOAA station 20 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots
16-Day Forecast — St. Helen
- Mon55°45°0%
- Tue58°43°0%
- Wed66°44°0%
- Thu69°46°1%
- Fri71°49°1%
- Sat72°46°1%
- Sun60°53°5%
- Mon74°53°6%
- Tue79°56°29%
- Wed71°55°30%
- Thu61°46°18%
- Fri55°39°13%
- Sat60°48°23%
- Sun58°44°16%
- Mon51°38°19%
- Tue55°35°17%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Fall planting + final harvests
As of September 21, the season's first frost (typically October 4) is approaching. Pick what frost-tender plants still carry before the next cold front. This city's planting calendar for September: plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, and carrots.
Sun & seasons in St. Helen
St. Helen sits in Roscommon County, where the year’s longest day runs 15h 32m of daylight and its shortest just 8h 50m — a swing of +6h 41m between the June and December solstices. Clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.
Detroit, the state’s largest city, lies about 152 miles to the SSE. The nearest town St. Helen tracks is Interlochen, roughly 70 miles to the WNW.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes | radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| July | tomatoes, peppers, beans, squash, fall brassicas, carrots | lettuce, peas, spinach, summer squash |
| August | garlic (overwinter) | lettuce, peas, tomatoes, peppers, beans, summer squash, garlic |
| September | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
| October | — | fall brassicas, carrots |
A year in weather
St. Helen peaks at about 68°F in July and bottoms near 19°F in January; June brings the heaviest rain (3.5 inches) and February the least (1.6 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 19° | 2.0″ | 13 |
| February | 20° | 1.6″ | 10 |
| March | 30° | 1.8″ | 9 |
| April | 42° | 3.4″ | 11 |
| May | 55° | 3.5″ | 12 |
| June | 64° | 3.5″ | 11 |
| July | 68° | 3.5″ | 11 |
| August | 67° | 3.4″ | 11 |
| September | 59° | 2.7″ | 11 |
| October | 47° | 3.3″ | 13 |
| November | 35° | 2.5″ | 12 |
| December | 26° | 2.1″ | 13 |
Regional context
Similar climates West Branch, MI, Roscommon, MI, Prudenville, MI
St. Helen's climate, from NOAA NCEI 1991-2020 station normals, pairs 19°F Januarys with 68°F Julys — a 49°F swing. About 33.6 inches of precipitation falls over roughly 137 days a year.
St. Helen's rain peaks in summer: June brings 3.5 inches over 11.4 thunderstorm-fed days, while February sees just 1.6 inches across 9.5 days under cooler, drier air. St. Helen shares that warm-season-wet pattern with places like West Branch, MI, Roscommon, MI and Prudenville, MI.
By May 15 the frosts ease in St. Helen, opening the season for kale, peas, spinach, and parsnips. In St. Helen, warm-season transplants — tomatoes, peppers, basil — wait two weeks past St. Helen's frost date. Around October 4, freezing nights resume in St. Helen and tender crops must come in. In about half of years, St. Helen's last freeze comes after May 15.
Similar climates: West Branch, MI, Roscommon, MI, Prudenville, MI, Rose City, MI, Houghton Lake, MI.
Frequently asked
- When does it freeze in St. Helen?
- St. Helen's last spring frost lands near May 15, and in St. Helen the first fall frost follows around October 4.
- What is the rainy season in St. Helen?
- St. Helen sees its heaviest rain in June (around 3.5 inches), part of roughly 34 inches a year.
- What is the warmest month in St. Helen?
- St. Helen peaks in July, when the mean runs near 68°F.
- What is the coldest month in St. Helen?
- January is St. Helen's coldest month, averaging about 19°F.
- When can I start a vegetable garden in St. Helen?
- In St. Helen, sow peas and hardy greens around May 15; St. Helen's tomatoes and peppers wait two weeks more.
- How many rainy days does St. Helen get?
- St. Helen averages about 137 days with measurable rain or snow each year.
- What hardiness zone is St. Helen?
- With January around 19°F, St. Helen's zone reflects that minimum — the USDA ZIP map confirms St. Helen's band.
- What is the 10-day forecast for St. Helen?
- St. Helen'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 St. Helen?
- See this week's day-by-day rain chances for St. Helen in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in St. Helen?
- Current conditions for St. Helen and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the St. Helen forecast updated?
- The St. Helen forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in St. Helen?
- Today's sunrise and sunset times for St. Helen 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 St. Helen?
- The next few days in St. Helen's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
St. Helen sits at 44.4°N; its climate zone is warm-summer humid continental (Köppen approximation).
ZIP codes in St. Helen
- 48656