How we pick

The method is the product: one source per place, named on the page, and rules anyone can re-run.

The data

All weather figures are the 1991–2020 U.S. Climate Normals published by NOAA's National Centers for Environmental Information. Each place is matched to the nearest station with complete temperature and precipitation normals; the station's name, its NOAA id, its distance from the town center, and its elevation are printed on every page for that place. Places whose nearest complete station was implausibly far were dropped from the launch list rather than guessed at. Daylight hours are computed for the middle of the month from the place's latitude and longitude.

The score

Every month starts at 100. For a sightseeing trip we deduct for: average highs outside the 65–75°F comfort core (progressively, both directions); nights below freezing; rain days (days with at least 0.01 in of rain) beyond six, at roughly two points each; heavy monthly rainfall; snow on the ground plan (sightseeing only); days that typically reach 90°F; and days below 0°F. Long days add up to 8 points back; very short winter days take up to 8 away. Beach places use a warmer comfort core (78–88°F) and treat any snow as disqualifying; ski towns are scored on snowfall and cold from November through April and as sightseeing towns the rest of the year. The top-scoring months (within two points of the best, and at least 62) are crowned ★ Best — at most three per season.

The hurricane overlay

Averages hide extremes. For Atlantic, Gulf, and Caribbean places, months inside hurricane season (June 1–November 30) are flagged in words, and the statistical peak months (mid-August through late October) are capped at a "risky" verdict no matter what the arithmetic said — a warm, dry-on-average September in San Juan is still hurricane season's peak. The overlay describes climatology, never a prediction about any specific trip.

Crowds

We do not publish crowd tiers yet. The only monthly crowd data we consider defensible is agency-published visitation (for example, National Park Service monthly visitor counts for park towns); until that layer is built and labeled, no page here guesses at crowds.

Packing lists

Every packing line is fired by a number printed on the same page (a typical low under 40°F triggers the insulated-coat line; ten or more rain days triggers the waterproof-shell line), so the advice can be audited against the data.

What these pages are not

Monthly weather summaries are historical averages for trip planning only — they are not forecasts, and the weather in any given month will differ. Averages describe what a month is typically like across thirty years; your trip gets one specific week. Check a real forecast (weather.gov) as your dates approach, especially in hurricane season.