St. Ann Highlands, CO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Ann Highlands, a community in Boulder County, Colorado.
Today
68°F
Patchy Smoke
Patchy smoke before noon, then patchy smoke and a slight chance of showers and thunderstorms. Mostly sunny. High near 68, with temperatures falling to around 62 in the afternoon. East wind around 7 mph. Chance of precipitation is 20%.
7-day forecast for St. Ann Highlands
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 68°F | Patchy Smoke | 7 mph E | 24% |
| Tonight | 49°F | Patchy Smoke | 1 to 6 mph SSE | 16% |
| Wednesday | 76°F | Mostly Sunny | 6 mph N | 2% |
| Wednesday Night | 50°F | Mostly Clear | 5 mph SW | 1% |
| Thursday | 82°F | Sunny | 6 mph NW | 2% |
| Thursday Night | 54°F | Clear | 5 mph NW | 1% |
| Friday | 84°F | Sunny | 2 to 6 mph NNE | 0% |
| Friday Night | 58°F | Mostly Clear | 2 to 6 mph SSW | 0% |
| Saturday | 85°F | Sunny | 6 mph N | 10% |
| Saturday Night | 60°F | Mostly Clear | 5 mph NW | 1% |
| Sunday | 85°F | Sunny | 5 mph N | 10% |
| Sunday Night | 61°F | Partly Cloudy | 5 mph NW | 8% |
| Monday | 83°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 5 mph N | 46% |
| Monday Night | 58°F | Chance Showers And Thunderstorms then Mostly Cloudy | 5 mph W | 25% |
Forecast source: National Weather Service (api.weather.gov) for St. Ann Highlands (39.987, -105.456). Updated through the day.
Growing snapshot for St. Ann Highlands
Last spring frost
Jun 5
First fall frost
Sep 16
Growing season
103 days
Hardiness zone
5b
More local growing data for St. Ann Highlands: nearby ZIP 80471 weather · frost dates · planting calendar · Colorado frost dates
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Climate data from the nearest NOAA station, Coal Creek Canyon, Co (3.3 mi from St. Ann Highlands). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.