Roy, Utah Weather
Pikas hayfeeding in granite peaks. Day 77 of spring. Read this microseason across nine climate regions →
Roy weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Overcast——87°55°—
- ThursdayJun 4Overcast——85°68°-2°
- FridayJun 5Clear——88°59°+3°
- SaturdayJun 6Overcast——91°62°+3°
- SundayJun 7Overcast——77°56°-14°
- MondayJun 8Overcast——85°51°+8°
- TuesdayJun 9Overcast——77°51°-8°
PM2.5 at 7.1 µg/m³ (AQI 39) with a 0.70 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust. AQI up 11 over the last 6 hours (gradual rise).
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 37 now. With UV 0.0 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 9 by mid-afternoon.
- Present
- AQI 37
- UV peak
- 0.0 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 9
PM × Wind × Precip
PM2.5 at 7.1 µg/m³ (AQI 39) with a 0.70 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.70
- 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).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 6:03 AM
- Moonset
- 3:30 PM
- In sign
- ♑︎ Capricorn
Pikas hayfeeding in granite peaks
Roy at a glance
- Today vs. normal: 5°F above the seasonal normal for this latitude
- Last frost: April 23 (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 4, 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.
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
Roy's warmest month is July (~78°F mean) and its coldest is January (~30°F). Rainfall peaks in May (2.6 inches) and bottoms out in July (0.6 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 30° | 2.5″ | 7 |
| February | 34° | 1.9″ | 6 |
| March | 44° | 2.3″ | 5 |
| April | 50° | 2.5″ | 5 |
| May | 60° | 2.6″ | 6 |
| June | 70° | 1.5″ | 4 |
| July | 78° | 0.6″ | 2 |
| August | 77° | 0.7″ | 2 |
| September | 67° | 1.5″ | 3 |
| October | 54° | 2.1″ | 4 |
| November | 41° | 1.7″ | 4 |
| December | 31° | 1.8″ | 5 |
Regional context
Roy sits within a cold semi-arid climate region — a cohort that shares similar temperature ranges, seasonal patterns, and growing conditions across nearby cities.
Similar climates: Salt Lake City, UT, Provo, UT, Ogden, UT, West Valley City, UT, Logan, UT.
Frequently asked
- When does it freeze in Roy?
- Roy's last spring frost typically falls around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Roy?
- May is the wettest month with about 2.6 inches of rain on average; the city receives roughly 22 inches annually.
- What is the warmest month in Roy?
- July is typically warmest, averaging about 78°F.
- What is the coldest month in Roy?
- January is typically coldest, averaging about 30°F.
- When can I start a vegetable garden in Roy?
- 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 Roy get?
- Roy averages about 51 rainy days per year.
- What hardiness zone is Roy?
- Roy'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
Roy, Utah sits in a cold semi-arid climate zone. January means hover near 30°F while July averages 78°F — a 48°F seasonal swing.
Across the year, Roy receives about 22 inches of precipitation spread over roughly 51 rainy days.
The rhythm of the year is set by latitude (41.2°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.