Frost Dates for 97814 — Baker City, Oregon

Half of springs at Baker City Municipal Airport, OR see their last 32°F night by May 25; only one in ten is past it by May 9, and one in ten still has one after June 16. Planting tender crops after June 4 leaves a 30% risk of a frost on them, after June 9 20%, and after June 16 10%. The 22 days between the even-odds date and the one-in-ten date is narrower than at 45% of the 103 Oregon stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.

In fall the first 32°F night comes by September 15 in half of years, as early as September 2 one year in ten, and holds off past October 1 one year in ten. A hard freeze of 28°F follows 12 days later, around September 27; in spring the one-in-ten date for 28°F is May 23, 24 days before the 32°F one. The freeze-free season lasts 111 days in a typical year, shorter than at 92% of the 103 Oregon stations; it reaches 133 days one year in ten and falls short of 85 one year in ten. On average 191 nights a year drop to 32°F or below. Severe cold of 16°F or below comes every winter, usually between November 4 and March 4.

July is the warmest month at Baker City Municipal Airport, OR, averaging 88°F by day and 49°F at night; December is the coldest at 37°F and 20°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 36% of years.

Warmth for growing adds up to 1,993 growing degree days a year (base 50°F), fewer than at 62% of the 103 Oregon stations. 27% of them (529) have built up by the end of June, and July adds the most, 575. Precipitation totals 9.1 inches a year, most in May (1.5") and least in August (0.4"); May to September bring 44% of it.

The nearest other station, Union, OR, 28 miles north of Baker City and 584 feet lower, has a last frost 14 days earlier (May 11), a first frost 11 days later (September 26), a season 25 days longer.

The first measurable snow (0.1 inch or more) in Baker City usually arrives around November 8, and the last of the season around April 6. Those are the middle dates across the winters of 1991–2020 at Rock Creek, OR, 14.2 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 49 days after the last snow.

ZIP 97814 is 3 miles from Baker City Municipal Airport, OR, which stands at 3,361 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 97814 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.