Frost Dates for Monroe, WI 53566
Last spring frost May 7 · First fall frost October 1 · 147 frost-free days · USDA Zone 5a
ZIP 53566 has about 14,900 people.
Moderate season: 147 frost-free days. Spring frost risk spans April 21–May 23 (32 days). Fall frost risk spans September 20–October 13 (23 days).
Frost probability for 53566
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 23 | May 7 | April 21 |
| Fall (first frost) | September 20 | October 1 | October 13 |
Dates come from NOAA 1971–2000 freeze probabilities at BRODHEAD WWTP (21.4 km away); the 50% date is the median year.
Which crops fit a 147-day season in Monroe
In Monroe (147 frost-free days, a moderate season), 37 of 56 planner crops fit outright, 18 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Apr 2 | May 21–May 28 | 105 | fits: 80 days to maturity, 105 available after May 21. | Jun 1 |
| Pepper | Mar 26 | May 21–May 28 | 105 | fits: 75 days to maturity, 105 available after May 21. | Jun 6 |
| Lettuce | Mar 12 | Apr 9–Apr 16 | 182 | two-plantings: Plant Apr 9 and again by Aug 10; both mature before Oct 8. | Aug 10 |
| Carrots | — | Apr 16–Apr 23 | 189 | fits: 70 days to maturity, 189 available after Apr 16. | Jul 30 |
| Cucumber | Apr 16 | May 21–May 28 | 119 | fits: 60 days to maturity, 119 available after May 21. | Jul 5 |
| Beans | — | May 14–May 28 | 133 | fits: 60 days to maturity, 133 available after May 14. | Jul 12 |
| Peas | — | Mar 12–May 21 | 210 | fits: 65 days to maturity, 210 available after Mar 12. | Jul 21 |
| Zucchini | Apr 23 | May 21–May 28 | 119 | fits: 55 days to maturity, 119 available after May 21. | Jul 10 |
| Onion | Feb 12 | Apr 9–Apr 23 | 182 | fits: 100 days to maturity, 182 available after Apr 9. | — |
| Spinach | — | Mar 12–Apr 30 | 224 | two-plantings: Plant Mar 12 and again by Aug 29; both mature before Oct 22. | Aug 29 |
| Kale | Feb 26 | Apr 9–Apr 23 | 196 | two-plantings: Plant Apr 9 and again by Aug 14; both mature before Oct 22. | Aug 14 |
| Broccoli | Mar 12 | Apr 9–Apr 23 | 182 | fits: 80 days to maturity, 182 available after Apr 9. | Jul 6 |
| Cabbage | Mar 12 | Apr 9–Apr 23 | 196 | fits: 70 days to maturity, 196 available after Apr 9. | Jul 30 |
| Radish | — | Mar 12–Jun 4 | 210 | two-plantings: Plant Mar 12 and again by Aug 30; both mature before Oct 8. | Aug 30 |
| Beets | — | Mar 12–Jun 4 | 210 | two-plantings: Plant Mar 12 and again by Jul 31; both mature before Oct 8. | Jul 31 |
| Potatoes | — | Apr 23–Apr 30 | 168 | fits: 90 days to maturity, 168 available after Apr 23. | — |
| Garlic | — | Oct 1 | 252 | overwinter: Plant Oct 1 to Oct 22; harvest the following summer. | Oct 22 |
| Strawberry | — | Apr 2–May 28 | 203 | perennial: A perennial: plant Apr 2; it fruits from the following year and keeps producing for several years. | — |
| Corn | Apr 9 | May 14–May 21 | 119 | fits: 75 days to maturity, 119 available after May 14. | Jun 13 |
| Pumpkin | Apr 23 | May 21–May 21 | 112 | fits: 100 days to maturity, 112 available after May 21. | — |
| Cauliflower | Mar 26 | Apr 30–May 14 | 161 | fits: 75 days to maturity, 161 available after Apr 30. | Jul 11 |
| Swiss Chard | Mar 12 | Apr 23–Apr 23 | 168 | two-plantings: Plant Apr 23 and again by Jul 31; both mature before Oct 8. | Jul 31 |
| Arugula | — | Mar 12–Jun 4 | 224 | two-plantings: Plant Mar 12 and again by Aug 29; both mature before Oct 22. | Aug 29 |
| Brussel Sprouts | Mar 12 | Apr 9–Apr 23 | 196 | fits: 100 days to maturity, 196 available after Apr 9. | Jun 30 |
| Butternut Squash | Apr 23 | May 21–May 28 | 112 | fits: 100 days to maturity, 112 available after May 21. | — |
| Eggplant | Mar 19 | May 21–May 28 | 105 | fits: 70 days to maturity, 105 available after May 21. | Jun 11 |
| Okra | Apr 9 | May 14–May 21 | 126 | two-plantings: Plant May 14 and again by Jul 10; both mature before Sep 17. | Jul 10 |
| Basil | Apr 2 | May 28–May 28 | 112 | fits: 60 days to maturity, 112 available after May 28. | Jul 5 |
| Cilantro | — | Apr 9–Apr 30 | 182 | two-plantings: Plant Apr 9 and again by Aug 5; both mature before Oct 8. | Aug 5 |
| Parsley | Feb 26 | May 14–May 21 | 147 | fits: 70 days to maturity, 147 available after May 14. | Jul 16 |
| Celery | Feb 26 | May 14–May 28 | 147 | fits: 120 days to maturity, 147 available after May 14. | May 27 |
| Scallions | Feb 26 | Apr 9–Apr 23 | 196 | two-plantings: Plant Apr 9 and again by Aug 9; both mature before Oct 22. | Aug 9 |
| Turnip | — | Apr 9–Apr 23 | 196 | two-plantings: Plant Apr 9 and again by Aug 19; both mature before Oct 22. | Aug 19 |
| Kohlrabi | — | Mar 26–Apr 9 | 210 | two-plantings: Plant Mar 26 and again by Aug 14; both mature before Oct 22. | Aug 14 |
| Bok Choy | Apr 9 | Apr 30–May 7 | 161 | two-plantings: Plant Apr 30 and again by Aug 10; both mature before Oct 8. | Aug 10 |
| Collards | Feb 26 | Apr 9–Apr 23 | 196 | two-plantings: Plant Apr 9 and again by Aug 9; both mature before Oct 22. | Aug 9 |
| Cantaloupe | Apr 23 | May 21–May 28 | 105 | fits: 85 days to maturity, 105 available after May 21. | May 27 |
| Chives | Feb 12 | May 14–May 21 | 161 | fits: 90 days to maturity, 161 available after May 14. | — |
| Dill | — | Mar 12–Jun 4 | 210 | two-plantings: Plant Mar 12 and again by Jul 31; both mature before Oct 8. | Jul 31 |
| Oregano | Feb 26 | May 14–May 21 | 161 | fits: 80 days to maturity, 161 available after May 14. | — |
| Rosemary | Feb 12 | May 14–May 21 | 147 | fits: 80 days to maturity, 147 available after May 14. | — |
| Sage | Mar 12 | May 14–May 21 | 161 | fits: 75 days to maturity, 161 available after May 14. | — |
| Thyme | Feb 26 | May 14–May 21 | 161 | fits: 90 days to maturity, 161 available after May 14. | — |
| Calendula | Mar 26 | Apr 23–May 7 | 168 | two-plantings: Plant Apr 23 and again by Aug 5; both mature before Oct 8. | Aug 5 |
| Cosmos | Apr 9 | May 7–May 21 | 133 | fits: 60 days to maturity, 133 available after May 7. | Jul 5 |
| Lavender | Feb 12 | May 7–May 21 | 168 | fits: 90 days to maturity, 168 available after May 7. | — |
| Marigolds | Mar 26 | May 7–May 14 | 133 | two-plantings: Plant May 7 and again by Jul 15; both mature before Sep 17. | Jul 15 |
| Melons | Apr 23 | May 21–May 28 | 105 | fits: 85 days to maturity, 105 available after May 21. | May 27 |
| Mint | — | May 7–May 21 | 168 | fits: 90 days to maturity, 168 available after May 7. | — |
| Nasturtiums | Apr 9 | May 7–May 14 | 133 | two-plantings: Plant May 7 and again by Jul 10; both mature before Sep 17. | Jul 10 |
| Pole Beans | — | May 14–May 28 | 126 | fits: 65 days to maturity, 126 available after May 14. | Jun 30 |
| Spaghetti Squash | Apr 23 | May 21–May 28 | 112 | fits: 90 days to maturity, 112 available after May 21. | May 29 |
| Sunflowers | — | May 7–May 21 | 133 | fits: 70 days to maturity, 133 available after May 7. | Jun 25 |
| Tomatillos | Mar 12 | May 14–May 21 | 112 | fits: 75 days to maturity, 112 available after May 14. | Jun 6 |
| Watermelon | Apr 23 | May 14–May 21 | 112 | fits: 80 days to maturity, 112 available after May 14. | Jun 1 |
| Yellow Squash | Apr 23 | May 21–May 28 | 119 | fits: 55 days to maturity, 119 available after May 21. | Jul 10 |
| Zinnias | Apr 9 | May 7–May 21 | 133 | fits: 60 days to maturity, 133 available after May 7. | Jul 5 |
Month by month in Monroe
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start indoors: Chives (Feb 12), Lavender (Feb 12), Onion (Feb 12), Rosemary (Feb 12), Celery (Feb 26), Collards (Feb 26), +5 more. |
| March | Start indoors: Broccoli (Mar 12), Brussel Sprouts (Mar 12), Cabbage (Mar 12), Lettuce (Mar 12), Sage (Mar 12), Swiss Chard (Mar 12), +6 more. Direct sow from: Arugula (Mar 12), Beets (Mar 12), Dill (Mar 12), Peas (Mar 12), Radish (Mar 12), Spinach (Mar 12), +1 more. |
| April | Start indoors: Basil (Apr 2), Tomato (Apr 2), Bok Choy (Apr 9), Corn (Apr 9), Cosmos (Apr 9), Nasturtiums (Apr 9), +11 more. Direct sow from: Cilantro (Apr 9), Turnip (Apr 9), Carrots (Apr 16), Potatoes (Apr 23). Transplant from: Broccoli (Apr 9), Brussel Sprouts (Apr 9), Cabbage (Apr 9), Collards (Apr 9), Kale (Apr 9), Lettuce (Apr 9), +6 more. Plant: Strawberry (Apr 2). |
| May | Direct sow from: Sunflowers (May 7), Beans (May 14), Pole Beans (May 14). Transplant from: Cosmos (May 7), Lavender (May 7), Marigolds (May 7), Mint (May 7), Nasturtiums (May 7), Zinnias (May 7), +23 more. Last frost around May 7. Last sowing dates: Cantaloupe (May 27), Celery (May 27), Melons (May 27), Spaghetti Squash (May 29). |
| June | Last sowing dates: Tomato (Jun 1), Watermelon (Jun 1), Pepper (Jun 6), Tomatillos (Jun 6), Eggplant (Jun 11), Corn (Jun 13), +3 more. |
| July | Last sowing dates: Basil (Jul 5), Cosmos (Jul 5), Cucumber (Jul 5), Zinnias (Jul 5), Broccoli (Jul 6), Nasturtiums (Jul 10), +13 more. |
| August | Last sowing dates: Calendula (Aug 5), Cilantro (Aug 5), Collards (Aug 9), Scallions (Aug 9), Bok Choy (Aug 10), Lettuce (Aug 10), +6 more. |
| September | First fall frost approaching (around October 1). Transplant fall brassicas. Sow spinach, arugula, and radishes. |
| October | Direct sow from: Garlic (Oct 1). First frost around October 1. Last sowing dates: Garlic (Oct 22). |
| November | Harvest remaining cold-hardy crops: kale, carrots, and beets. Plant garlic bulbs for next year. |
| December | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
Frequently Asked Questions
What is the last frost date for Monroe, WI (ZIP 53566)?
The median last spring frost date for Monroe, WI (ZIP code 53566) is around May 7. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area. One year in ten frost ends before April 21; one in ten it runs past May 23.
What is the first fall frost date in Monroe, WI?
The median first fall frost date for Monroe, WI is around October 1. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses. The first frost arrives around September 20 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Monroe, WI?
The frost-free growing season in Monroe is about 147 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side. In Monroe (147 frost-free days, a moderate season), 37 of 56 planner crops fit outright, 18 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Monroe, WI?
Monroe, WI is in USDA hardiness zone 5a (2023 USDA Plant Hardiness Zone Map). Zones come from the average coldest winter temperature, so they tell you which perennials survive the winter; the frost dates on this page tell you when to plant.
When should I start tomatoes indoors in Monroe, WI?
Start tomatoes indoors Apr 2 and plant out May 21 in Monroe. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Monroe?
Two: plant Apr 9 and again by Aug 10; both mature before Oct 8.
When do I plant garlic in Monroe?
Oct 1 to Oct 22; it overwinters and is ready the following summer.
Which nearby ZIP has a longer season?
Mount Horeb (ZIP 53572) has 155 frost-free days, 8 more than Monroe (ZIP 53566). See Mount Horeb ZIP 53572 frost dates
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