NOAA NCEI — U.S. Climate Normals 1991–2020
Monthly climatology (average highs and lows, precipitation frequency, workable-day counts) is computed from the daily normals dataset published by NOAA's National Centers for Environmental Information: variables DLY-TMAX-NORMAL, DLY-TMIN-NORMAL, DLY-PRCP-PCTALL-GE001HI, and DLY-PRCP-PCTALL-GE050HI, per station, 1991–2020 base period. NOAA data is a U.S. Government work in the public domain. Each city page names its station and distance in the footer.
Open-Meteo
The live 10-day window check fetches forecasts from the Open-Meteo API directly from your browser. Weather data by Open-Meteo.com, licensed under CC BY 4.0. Open-Meteo aggregates national weather-service models; forecasts are theirs, verdicts are ours.
City locations & population
City names, coordinates, and populations come from the SimpleMaps US Cities Database (Basic, free tier), used under its license with this attribution.
Weather-rule thresholds
The rule tables on this site are a consensus of typical label requirements and published application guidance across classes of sources, restated in our own words:
- Deck stain, exterior paint, and roof coating: application guidelines of the major U.S. architectural-coatings manufacturers (the Behr/Sherwin-Williams class of consumer brands) and their low-temperature formula lines.
- Driveway sealer: application and cure guidance from major asphalt-sealer manufacturers.
- Concrete: bagged-mix producer guidance and American Concrete Institute (ACI) hot- and cold-weather concreting practice, scoped on this site to small DIY pours only.
- Grass seed: germination guidance from major seed producers and university extension programs, modeled for cool-season grasses.
No threshold on this site quotes any single product. Your product's label always wins. The complete machine-readable ruleset, and how it is scored, is on the methodology page.
Standards & guidance by task
The consensus thresholds trace to these bodies. Names stay in plain text; the icon opens the source in a new tab (marked nofollow).
Deck Staining
- USDA Forest Products Laboratory
Federal lab guidance on choosing and applying penetrating finishes for wood decks.
- USDA FPL Wood Handbook
Reference handbook with a chapter on exterior wood finishing and weathering.
- North American Deck and Railing Association
Industry association offering deck safety, maintenance, and inspection resources for homeowners.
- PaintCare
Nonprofit stewardship program for recycling leftover stains, sealers, and paints.
Exterior Painting
- US EPA Lead RRP Program
Federal rules for safely disturbing lead paint on pre-1978 homes.
- American Coatings Association
Paint industry association covering coatings science, application, and safety guidance.
- PaintCare
Nonprofit paint stewardship program for storing and recycling leftover exterior paint.
- USDA FPL Finishing Wood
Wood Handbook chapter on paint performance, weathering, and moisture on exterior wood.
Driveway Sealing
- Asphalt Institute
Engineering FAQs covering when and how to seal asphalt driveways.
- Pavement Coatings Technology Council
Sealcoat industry FAQs on application, drying, curing, and weather requirements.
- US Geological Survey
Federal research on coal-tar sealcoat, PAHs, and environmental health impacts.
- Minnesota Pollution Control Agency
State agency guidance on coal-tar sealant bans and safer asphalt-based alternatives.
Concrete Pouring
- American Concrete Institute (Hot Weather)
ACI standards and guidance for placing concrete in hot weather.
- American Concrete Institute (Cold Weather)
ACI standards and guidance for protecting concrete during cold weather.
- American Cement Association
Formerly Portland Cement Association; covers concrete placement, curing, and weather considerations.
- NRMCA Concrete in Practice
Ready-mixed concrete association tip sheets including hot and cold weather concreting.
Roof Coating
- Roof Coatings Manufacturers Association
Trade association for roof coatings with technical and application resources.
- Asphalt Roofing Manufacturers Association
Industry association guidance on asphalt roofing systems, maintenance, and coatings.
- National Roofing Contractors Association
Professional roofing association with homeowner guidance and technical best practices.
- US EPA Heat Islands
Federal overview of cool roof coatings, benefits, and climate considerations.
Lawn Seeding
- University of Minnesota Extension
Extension guide to seeding timing, methods, and establishment for home lawns.
- Penn State Extension
University guidance on lawn establishment, seeding windows, and turfgrass selection.
- Purdue Turfgrass Science
Purdue turf program publications on lawn seeding, renovation, and care.
- Cornell Turfgrass
Cornell turfgrass program with lawn care and seeding guidance for homeowners.
Image credits
Photography is used under free licenses; the icon opens each source page.
- hero-home — Binyamin Mellish, Pexels License
- deck-staining — Pixabay, Pexels License
- exterior-painting — Dave_S. from Witney, England (Flickr), CC-BY 2.0
- driveway-sealing — Eyes2Soul, Pexels License
- concrete-pouring — SÀI GÒN CÔNG TY CP SẢN XUẤT - THƯƠNG MẠI, Pexels License
- roof-coating — Ryan Stephens, Pexels License
- lawn-seeding — Rachel Landers (U.S. DoD / DVIDS, Marine Corps Base Camp Blaz), Public Domain (U.S. government work)
- hero-tools — Ulrick Trappschuh, Pexels License
Type
Headings are set in IBM Plex Sans Condensed (© IBM Corp.), self-hosted under the SIL Open Font License 1.1. Body text uses your system's native font stack. No third-party CDNs, trackers, or analytics load from this site.