Lawn Care Calendar from Local Temperature History

Informational only. Not for navigation, safety, emergency, financial, medical, or legal decisions. Check the official source before you rely on it.

Enter a location and get your lawn timing from 30 years of local weather station temperatures instead of a zone map:

• Crabgrass preventer (pre-emergent) window: average start and end dates, plus early-year and late-year dates
• Crabgrass germination window (when to scout for breakthroughs)
• Spring broadleaf weed control window
• Last spring frost and first fall frost (32 F or 28 F)
• Where this year stands: degree days to date, and whether you are before, in or past each window

How it works

The tool finds the nearest weather station with daily temperatures since 1991 and current readings. It counts growing degree days from Feb 15 each year, 1991 to 2020, and finds the dates each published threshold was reached:

• Crabgrass preventer: base 32 F, 250 to 500 degree days (Michigan State University GDD Tracker, Calhoun 2004)
• Crabgrass germination: base 50 F, 200 to 600 (Michigan State University GDD Tracker)
• Spring broadleaf: base 50 F, 110 to 600 (Purdue Broadleaf Timer, as listed by MSU GDD Tracker)

How to use (no code)

1. Type a location name, latitude and longitude. 2. Click Start. It takes a few seconds and returns 5 rows.

Limits

The models were built for cool-season lawns in the Midwest and Northeast. For warm-season southern lawns, use your local extension calendar. Average windows are not a forecast; a warm or cold spring shifts them, so check the "this year" columns. Mowing and fertilizer timing are not included because no published temperature rule was used for them.

Disclaimer

Informational only. Not for navigation, safety, emergency, financial, medical, or legal decisions. Check the official source before you rely on it. This is an independent tool by Standard Work Co. It is not affiliated with, endorsed by, or sponsored by any government agency or university named here. Names are used only to say where the data and rules come from. The data comes from public sources and is passed through as published, only reformatted and summarized. Weather data can be preliminary, late, missing, revised, or wrong, and this tool can fail too. Provided "as is" with no warranty of any kind, including accuracy, completeness, or timeliness. Liability is limited as stated in the Apify Standard Actor Contract for this tool. Always follow the product label. This tool does not recommend products, rates, or application methods.

Data sources and credits

Daily station temperatures: RCC-ACIS (data.rcc-acis.org), NOAA Regional Climate Centers. Timing rules: Michigan State University GDD Tracker (gddtracker.msu.edu/about) and Purdue University research as listed there.