Weather and climate
- Daily weather history and 1991–2020 normals: Applied Climate Information System (ACIS) web services of NOAA's Regional Climate Centers, rcc-acis.org. Daily high, low and mean temperature at each city's airport station from late 2004 to yesterday, refreshed every run. Data from NOAA and the National Weather Service is in the US public domain.
- 7-day forecasts: National Weather Service API, api.weather.gov. Public domain.
Soil measurements
- Soil Climate Analysis Network (SCAN): USDA Natural Resources Conservation Service, via the AWDB REST API. Used to fit and test the soil model and to show the nearest sensor's latest reading. US government work, public domain.
Places and ZIP codes
- City locations, populations and ZIP code areas: US Census Bureau 2023 Gazetteer files and 2023 city population estimates. ZIP lookups use Census ZIP Code Tabulation Areas, which are close to, but not exactly, USPS ZIP codes. Public domain.
Lawn-care thresholds
The soil temperatures that trigger each task come from extension and university sources:
- Timing crabgrass preemergence applications in spring, Michigan State University Extension
- About GDDTracker (crabgrass PRE window, 250–500 GDD base 32°F), Michigan State University
- Crabgrass Pre-emergence Timer, University of Wisconsin–Madison Turfgrass Science
- It Is (Almost) Time for Fall Seeding of Cool-Season Grasses, NC State University TurfFiles
- Mild winter: what does it mean for overseeding or dormant seeding?, Rutgers Turfgrass Blog
- Time to repair, establish home lawns, University of Kentucky College of Agriculture
- Annual Bluegrass Control in Residential Turfgrass (B 1394), University of Georgia Cooperative Extension
- Fall fertilization of home lawns, Purdue University
- Establishing Bermudagrass Pasture, NC State Extension, Polk County
Pictures
- “Poa pratensis lawn” by Ethan2039, CC BY-SA 4.0, via Wikimedia Commons.
- “Cynodon dactylon RF” by Robert Flogaus-Faust, CC BY 4.0, via Wikimedia Commons.
- “Digitaria sanguinalis (3874047095)” by Matt Lavin, CC BY-SA 2.0, via Wikimedia Commons.
- “Soil profile with silt, loam, and clay” by Rivadavia.vila, CC0, via Wikimedia Commons.
- “Digitaria filiformis BB-1913” by N. L. Britton and A. Brown, Public domain, via Wikimedia Commons.
- “Festuca arundinacea” by Bildoj, CC BY-SA 3.0, via Wikimedia Commons.
Type
Libre Franklin and Source Serif 4, both under the SIL Open Font License, served from this site.
What is ours
The soil estimates, normals of the estimates, threshold dates, statuses and text are produced by this site. You are welcome to cite them with a link. The underlying government data is free to use from the sources above.