Frost Dates for 97355 — Lebanon, Oregon

Half of springs at Lebanon, OR see their last 32°F night by March 14; only one in ten is past it by February 18, and one in ten still has one after April 14. Planting tender crops after March 25 leaves a 30% risk of a frost on them, after April 1 20%, and after April 14 10%. The 31 days between the even-odds date and the one-in-ten date is wider than at 91% 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 November 18 in half of years, as early as October 27 one year in ten, and holds off past December 15 one year in ten. A hard freeze of 28°F follows 22 days later, around December 10; in spring the one-in-ten date for 28°F is March 8, 37 days before the 32°F one. The freeze-free season lasts 248 days in a typical year, longer than at 84% of the 103 Oregon stations; it reaches 286 days one year in ten and falls short of 210 one year in ten. On average 39 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 32 days longer, to about April 15, and return around October 28. Nights of 24°F, cold enough to damage hardier plants, come in 66% of winters and 16°F in 11%.

August is the warmest month at Lebanon, OR, averaging 86°F by day and 56°F at night; December is the coldest at 47°F and 36°F. From May to September the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 66% of years and April still brings one in 20% of years.

Warmth for growing adds up to 2,778 growing degree days a year (base 50°F), more than at 83% of the 103 Oregon stations. 30% of them (837) have built up by the end of June, and August adds the most, 640.

The nearest other station, Foster Dam, OR, 12 miles southeast of Lebanon and 220 feet higher, has a last frost 29 days later (April 12), a first frost 21 days earlier (October 28), a season 51 days shorter.

Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Waterloo, OR, 1.2 miles away, so there is no typical first-snow date to plan around.

ZIP 97355 is 2 miles from Lebanon, OR, which stands at 330 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 97355 in zone 8b, the band where the coldest night of the year averaged 15 to 20°F (-9.4 to -6.7°C) over 1991–2020; a zone describes winter lows, not frost dates.