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.
Tonight
46°F
Chance Showers And Thunderstorms then Partly Cloudy
A chance of showers and thunderstorms before 8pm, then a slight chance of showers and thunderstorms between 8pm and 9pm. Partly cloudy, with a low around 46. West wind around 6 mph. Chance of precipitation is 30%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for St. Ann Highlands
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 46°F | Chance Showers And Thunderstorms then Partly Cloudy | 6 mph W | 29% |
| Saturday | 64°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 6 mph SSW | 72% |
| Saturday Night | 43°F | Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms | 2 mph WSW | 39% |
| Sunday | 61°F | Chance Showers And Thunderstorms | 1 to 5 mph NW | 30% |
| Sunday Night | 41°F | Slight Chance Rain Showers then Mostly Clear | 2 mph WNW | 23% |
| Monday | 62°F | Sunny | 0 to 6 mph SE | 5% |
| Monday Night | 44°F | Mostly Clear | 2 mph NNW | 6% |
| Tuesday | 66°F | Mostly Sunny then Chance Showers And Thunderstorms | 2 mph E | 42% |
| Tuesday Night | 46°F | Chance Showers And Thunderstorms then Partly Cloudy | 1 mph SSW | 25% |
| Wednesday | 66°F | Partly Sunny then Chance Showers And Thunderstorms | 3 mph ENE | 41% |
| Wednesday Night | 46°F | Slight Chance Rain Showers then Mostly Cloudy | 1 mph SSW | 23% |
| Thursday | 65°F | Mostly Sunny then Chance Showers And Thunderstorms | 1 to 5 mph N | 28% |
| Thursday Night | 47°F | Chance Rain Showers then Mostly Cloudy | 2 mph SSW | 28% |
| Friday | 67°F | Mostly Sunny then Chance Showers And Thunderstorms | 1 to 5 mph SSW | 30% |
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 Sep 19, 2026.