USDA Hardiness Zone 4b
Frost Dates for 55013 — Chisago City, Minnesota
NOAA 1991–2020 normals from Forest Lake 5NE, MN (905 ft), 2 miles south.
Updated
In Chisago City, the last spring frost (32°F) is around May 3 in half of years and has passed by May 19 in nine years out of ten. The first fall frost comes around October 5, as early as September 22 one year in ten, leaving a typical freeze-free season of 154 days (NOAA, Forest Lake 5NE, MN).
- Last spring frost
- May 3
- First fall frost
- October 5
- Growing season
- 154 days
- Hardiness zone
- 4b
50% probability
50% probability
freeze-free, 50%
-25 to -20°F (-31.7 to -28.9°C) coldest night
- First snow
- November 9
- Last snow
- April 14
- Winters with snow
- 100%
- Snow per year
- 51.6"
median, 1991–2020
median, 1991–2020
28 of 28 observed
NOAA normal
Frost risk by date in Chisago City
Half of springs at Forest Lake 5NE, MN see their last 32°F night by May 3; only one in ten is past it by April 20, and one in ten still has one after May 19. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 13 20%, and after May 19 10%. The 16 days between the even-odds date and the one-in-ten date is wider than at 77% of the 142 Minnesota stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 5 in half of years, as early as September 22 one year in ten, and holds off past October 20 one year in ten. A hard freeze of 28°F follows 12 days later, around October 17; in spring the one-in-ten date for 28°F is May 6, 13 days before the 32°F one. The freeze-free season lasts 154 days in a typical year, longer than at 61% of the 142 Minnesota stations; it reaches 174 days one year in ten and falls short of 132 one year in ten. On average 161 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 11 days longer, to about May 14, and return around September 28. Severe cold of 16°F or below comes every winter, usually between November 12 and March 31.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 30 | May 4 | May 8 | May 11 | May 14 | May 16 | May 19 | May 23 | May 27 |
| 32°F | Apr 20 | Apr 25 | Apr 29 | May 1 | May 3 | May 6 | May 9 | May 13 | May 19 |
| 28°F | Apr 10 | Apr 14 | Apr 18 | Apr 21 | Apr 24 | Apr 26 | Apr 29 | May 2 | May 6 |
| 24°F | Apr 2 | Apr 5 | Apr 8 | Apr 12 | Apr 15 | Apr 18 | Apr 21 | Apr 24 | Apr 28 |
| 20°F | Mar 23 | Mar 30 | Apr 1 | Apr 3 | Apr 6 | Apr 9 | Apr 11 | Apr 15 | Apr 20 |
| 16°F | Mar 13 | Mar 19 | Mar 24 | Mar 28 | Mar 31 | Apr 2 | Apr 4 | Apr 7 | Apr 12 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 15 | Sep 19 | Sep 23 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 6 | Oct 10 |
| 32°F | Sep 22 | Sep 27 | Sep 30 | Oct 3 | Oct 5 | Oct 8 | Oct 12 | Oct 16 | Oct 20 |
| 28°F | Oct 1 | Oct 5 | Oct 9 | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 27 | Nov 1 |
| 24°F | Oct 12 | Oct 18 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 12 |
| 20°F | Oct 23 | Oct 28 | Nov 1 | Nov 3 | Nov 5 | Nov 9 | Nov 12 | Nov 15 | Nov 20 |
| 16°F | Oct 31 | Nov 3 | Nov 6 | Nov 10 | Nov 12 | Nov 15 | Nov 18 | Nov 22 | Nov 27 |
Freeze probabilities 1991–2020 at Forest Lake 5NE, MN, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 55013 →Compare Chisago City with another place →
Weather by month in Chisago City
July is the warmest month at Forest Lake 5NE, MN, averaging 83°F by day and 60°F at night; January is the coldest at 24°F and 3°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 62% of years.
Warmth for growing adds up to 2,620 growing degree days a year (base 50°F), more than at 72% of the 142 Minnesota stations. 33% of them (857) have built up by the end of June, and July adds the most, 676. Precipitation totals 33.2 inches a year, most in July (4.7") and least in January (0.9"); May to September bring 63% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 24 | 3 | 0.9 | 100% | 31 | 0 |
| Feb | 30 | 6 | 0.9 | 100% | 27 | 0 |
| Mar | 43 | 19 | 1.7 | 100% | 26 | 6 |
| Apr | 58 | 33 | 3.0 | 100% | 13 | 59 |
| May | 70 | 45 | 4.4 | 62% | 2 | 264 |
| Jun | 79 | 56 | 4.5 | 0% | 0 | 527 |
| Jul | 83 | 60 | 4.7 | 0% | 0 | 676 |
| Aug | 82 | 58 | 4.0 | 0% | 0 | 617 |
| Sep | 74 | 50 | 3.2 | 31% | 1 | 365 |
| Oct | 60 | 37 | 2.9 | 99% | 8 | 98 |
| Nov | 43 | 24 | 1.8 | 100% | 23 | 9 |
| Dec | 29 | 11 | 1.2 | 100% | 30 | 0 |
Monthly normals 1991–2020 at Forest Lake 5NE, MN (905 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, St Croix Falls, WI, 12 miles east of Chisago City and 155 feet lower, has a last frost 1 day later (May 4), a first frost 3 days later (October 8), a season 2 days longer.
When it snows in Chisago City, Minnesota
The first measurable snow (0.1 inch or more) in Chisago City usually arrives around November 9, and the last of the season around April 14. Those are the middle dates across the winters of 1991–2020 at Forest Lake 5NE, MN, 2.4 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 19 days after the last snow.
Planting calendar for 55013
| When | What to do |
|---|---|
| February 22 – March 8 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 8 – March 22 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 5 – April 19 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 3 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 13 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 21 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 5 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 55013 is 2 miles from Forest Lake 5NE, MN, which stands at 905 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 6 other ZIP codes share the station; its figures are presented in full for 55025 (Forest Lake). The 2023 USDA Plant Hardiness Zone Map lists ZIP 55013 in zone 4b, the band where the coldest night of the year averaged -25 to -20°F (-31.7 to -28.9°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across Minnesota →
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.