Frost Dates for 99574 — Cordova, Alaska

Half of springs at Cordova M K Smith Airport, AK see their last 32°F night by May 23; only one in ten is past it by May 7, and one in ten still has one after June 5. Planting tender crops after May 27 leaves a 30% risk of a frost on them, after May 31 20%, and after June 5 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 46% of the 37 Alaska stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 19 in half of years, as early as September 5 one year in ten, and holds off past October 2 one year in ten. A hard freeze of 28°F follows 13 days later, around October 2; in spring the one-in-ten date for 28°F is May 18, 18 days before the 32°F one. The freeze-free season lasts 118 days in a typical year, shorter than at 70% of the 37 Alaska stations; it reaches 139 days one year in ten and falls short of 98 one year in ten. On average 165 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 12, and return around September 1. Severe cold of 16°F or below comes every winter, usually between November 9 and March 26.

July is the warmest month at Cordova M K Smith Airport, AK, averaging 62°F by day and 48°F at night; January is the coldest at 34°F and 19°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 18% of years.

Warmth for growing adds up to 388 growing degree days a year (base 50°F), fewer than at 86% of the 37 Alaska stations. 21% of them (81) have built up by the end of June, and July adds the most, 145. Precipitation totals 86.3 inches a year, most in September (13.2") and least in April (4.5"); May to September bring 45% of it.

The first measurable snow (0.1 inch or more) in Cordova usually arrives around November 9, and the last of the season around April 1. Those are the middle dates across the winters of 1991–2020 at Cordova N, AK, 13.2 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 52 days after the last snow.

ZIP 99574 is 2 miles from Cordova M K Smith Airport, AK, which stands at 31 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 99574 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.