Frost Dates for 99156 — Newport, Washington

Half of springs at Newport, WA see their last 32°F night by May 12; only one in ten is past it by April 28, and one in ten still has one after May 29. Planting tender crops after May 18 leaves a 30% risk of a frost on them, after May 23 20%, and after May 29 10%. The 17 days between the even-odds date and the one-in-ten date is narrower than at 66% of the 113 Washington stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 21 in half of years, as early as September 5 one year in ten, and holds off past October 5 one year in ten. A hard freeze of 28°F follows 11 days later, around October 2; in spring the one-in-ten date for 28°F is May 14, 15 days before the 32°F one. The freeze-free season lasts 130 days in a typical year, shorter than at 93% of the 113 Washington stations; it reaches 151 days one year in ten and falls short of 107 one year in ten. On average 169 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 20 days longer, to about June 1, and return around September 6. Severe cold of 16°F or below comes every winter, usually between November 19 and March 4.

July is the warmest month at Newport, WA, averaging 84°F by day and 51°F at night; December is the coldest at 32°F and 23°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 83% of years.

Warmth for growing adds up to 1,824 growing degree days a year (base 50°F), fewer than at 65% of the 113 Washington stations. 28% of them (518) have built up by the end of June, and July adds the most, 538.

The nearest other station, Deer Park Airport, WA, 18 miles southwest of Newport, has a last frost 10 days later (May 22), a first frost 7 days earlier (September 14), a season 18 days shorter.

The first measurable snow (0.1 inch or more) in Newport usually arrives around November 30, and the last of the season around March 5. Those are the middle dates across the winters of 1991–2020 at Newport, WA, 5.9 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 68 days after the last snow.

ZIP 99156 is 6 miles from Newport, WA, which stands at 2,162 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 99156 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.