Cedar Rapids, IA Frost Dates
Published: February 1, 2026 · Updated: April 23, 2026
USDA Zone 5b
Last Spring Frost
April 7
Safe to transplant after this date
First Fall Frost
October 22
Protect tender plants before this date
Frost-Free Season
198 days
Early April to Early November
312 days until last frost in Cedar Rapids — April 7
Cedar Rapids’s location in USDA zone 5b creates one of the shorter growing seasons in the continental US. With a last spring frost of April 7 and first fall frost of October 22, the frost-free window is just 198 days — every gardening and lawn care decision must be precisely timed.
Complete Planting Calendar for Cedar Rapids
Lawn Care Timing for Cedar Rapids
Based on Cedar Rapids's USDA zone 5b frost dates: The last frost of April 7 marks when warm-season grasses begin recovering. Apply spring fertilizer in Early April when soil reaches 55°F. The first fall frost of October 22 sets your deadlines — complete overseeding by August 20–September 20 and apply winterizer by Early November.
USDA Zone 5b Summary
About 6.5 months frost-free. Good cool-season lawn climate extending into November.
Frequently Asked Questions
What is the last frost date in Cedar Rapids, IA?
The average last spring frost in Cedar Rapids is April 7. This is based on USDA zone 5b historical averages. Plan transplanting and spring lawn care around this date — wait 2 weeks after for frost-sensitive plantings.
When is the first fall frost in Cedar Rapids?
Cedar Rapids’s average first fall frost is October 22. This sets deadlines for fall overseeding (must be done 6 weeks before) and winterizer application (by Early November).
When should I plant tomatoes in Cedar Rapids?
Transplant tomato seedlings outdoors after April 7. Start seeds indoors Late January. Direct sow warm-season crops after april 15.
When should I overseed my lawn in Cedar Rapids?
The prime overseeding window in Cedar Rapids is August 20–September 20. This ensures warm soil for germination before the first fall frost on October 22.
When should I apply winterizer in Cedar Rapids?
Apply winterizer fertilizer in Cedar Rapids by Early November. This high-potassium application hardens grass cell walls before freeze damage. Your first fall frost of October 22 is the hard deadline.