The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Havre it's a good idea to figure out when it's the best time to plant watermelon.

Planting Calendar for Watermelon

Frost tolerance for watermelon:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably not a good idea to plant watermelon until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant watermelon in Havre is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant watermelon and expect a good harvest is probably August. If you wait any later than that and your watermelon may not have a chance to fully mature. Starting your watermelon indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Havre the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -30°F.

Just be sure to remember that USDA zone info for Havre may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Havre last frost occurs after May 15 so make sure that you are prepared to cover your watermelon in the event of one of those late frosts.

USDA Zone Info for Havre

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Havre

You may be interested in your other planting guides for Havre.