Firestone, Colorado Weather
Pikas hayfeeding in granite peaks. Day 76 of spring. Read this microseason across nine climate regions →
Firestone weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Light Rain32%0.06″87°50°—
- ThursdayJun 4Overcast——92°50°+5°
- FridayJun 5Partly Cloudy——89°58°-3°
- SaturdayJun 6Light Drizzle11%0.02″96°60°+7°
- SundayJun 7Overcast23%—96°58°0°
- MondayJun 8Overcast42%—92°62°-4°
- TuesdayJun 9Overcast42%—99°59°+7°
PM2.5 at 11.7 µg/m³, PM10 at 15.5 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 39. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
- Present
- AQI 39
- UV peak
- 8.3 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 22
PM × Wind × Precip
PM2.5 at 11.7 µg/m³, PM10 at 15.5 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.75
- Wind
- breezy
- Recent rain
- 1h 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
- 4:53 AM
- Moonset
- 2:01 PM
- In sign
- ♑︎ Capricorn
Pikas hayfeeding in granite peaks
Firestone at a glance
- Today vs. normal: 77°F — typical for the season
- Last frost: April 17 (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
Warm-season window is open
As of June 3, the last spring frost has passed for most years. Transplant tomatoes, peppers, eggplants, basil, and cucurbits (cucumbers, squash, melons) now. Direct-sow beans and corn into warm soil.
SPC Convective Outlook
Storm Prediction Center — Firestone
SPC has placed Firestone in the Marginal Risk category for severe thunderstorms today.
- TODAYMRGLMarginal Risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3NONENo severe 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
Firestone's warmest month is July (~73°F mean) and its coldest is January (~29°F). Rainfall peaks in April (2.0 inches) and bottoms out in December (0.5 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 29° | 0.6″ | 2 |
| February | 32° | 0.6″ | 2 |
| March | 42° | 1.2″ | 3 |
| April | 48° | 2.0″ | 5 |
| May | 57° | 2.0″ | 6 |
| June | 67° | 1.8″ | 5 |
| July | 73° | 1.7″ | 3 |
| August | 71° | 1.9″ | 3 |
| September | 63° | 1.3″ | 4 |
| October | 50° | 1.0″ | 3 |
| November | 39° | 0.8″ | 3 |
| December | 30° | 0.5″ | 1 |
Regional context
Firestone's baseline climate, derived from NOAA NCEI 1991-2020 normals at the nearest reporting station, swings from a January mean of 29°F to a July mean of 73°F — a 44°F seasonal arc typical of the mid-latitude bands. Annual precipitation runs about 15.2 inches spread across roughly 40 days with measurable rain or snow each year.
Precipitation runs summer-dominant here: April averages 2.0 inches across 5.1 days with measurable rain, driven mostly by warm-season storms and thunderstorm activity, while December drops to just 0.5 inches across 1.0 rainy days under drier cool-season air. The warm-season-wet rhythm lines Firestone up with places like Frederick, CO, Mead, CO and Dacono, CO, where the May-September stretch delivers the bulk of the year's precipitation.
The frost-sensitive growing window opens around mid-April, when overnight lows reliably clear freezing for cool-season crops like kale, peas, spinach, and parsnips. Heat-loving transplants like tomatoes, peppers, and squash generally hold off for another 10-14 days to clear the last spring frost risk window. The window closes around mid-November, when overnight lows resume dipping below freezing and frost-tender plants need protection or harvest. These dates represent 30-year central tendencies; actual year-to-year variation can shift either bookend by 7-14 days, and local microclimate features within Firestone — cold-air drainage on calm clear nights, slope aspect, distance from any nearby lake or river — can push the practical frost window earlier or later than the regional average.
Similar climates: Frederick, CO, Mead, CO, Dacono, CO, Platteville, CO, Longmont, CO.
Frequently asked
- When does it freeze in Firestone?
- Firestone's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Firestone?
- April is the wettest month with about 2.0 inches of rain on average; the city receives roughly 15 inches annually.
- What is the warmest month in Firestone?
- July is typically warmest, averaging about 73°F.
- What is the coldest month in Firestone?
- January is typically coldest, averaging about 29°F.
- When can I start a vegetable garden in Firestone?
- 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 Firestone get?
- Firestone averages about 40 rainy days per year.
- What hardiness zone is Firestone?
- Firestone'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
Firestone, Colorado sits in a cold semi-arid climate zone. January means hover near 29°F while July averages 73°F — a 44°F seasonal swing.
Across the year, Firestone receives about 15 inches of precipitation spread over roughly 40 rainy days.
The rhythm of the year is set by latitude (40.2°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.