One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Rapid City it's a good idea to figure out when it's a good idea to plant watermelon.

Planting Calendar for Watermelon

Frost tolerance for watermelon:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Watermelon do not do well in cold weather which tells us that it is necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant watermelon in Rapid City is April. However, you really should wait until May 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. You probably don't want to wait any later than that or else your watermelon may not have a chance to really do well. You can get started a few weeks earlier by starting your watermelon indoors.

Last Frost Date

In Rapid City the average date of last frost happens on April 15. You can expect an average low temperature of -20°F in the coldest months of winter.

Remember that USDA zone info for Rapid City is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Rapid City there is a last frost after April 15 so always be ready to cover your watermelon if you have a late frost.

USDA Zone Info for Rapid City

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Rapid City

You may be interested in your other planting guides for Rapid City.