Las Vegas heat and marriage licenses

This comparison finds no clear simple heat effect after accounting for the year, month and weekday. The adjusted correlation is 0.03, with 0.1% shared residual variance. That is an association check, not a causal estimate. The full-day comparison joins 6,931 dates from the license files to the airport's daily maximum temperature. The result does not support telling couples that hot weather by itself drives the bureau's daily volume.

The temperature source is NOAA GHCN-Daily station USW00023169, listed as MCCARRAN INTL AP in the station inventory. The verified station coordinates identify the Las Vegas airport site. Its daily file supplies maximum temperature; missing values and quality-flagged observations are excluded. Station identification, the inventory and the daily file were fetched from the official NCEI service. The airport reading is a local weather observation, not a temperature inside the licensing office or at every wedding venue.

The chart pools days into daily maximum-temperature bands, in Celsius. Each bar is the average number of licenses issued on days in that band. It is a descriptive starting point: hot and cool days occur in different parts of the calendar. The unadjusted correlation is 0.13. Reading the bars alone as a weather effect would mix temperature with the yearly calendar, weekdays and the long change in licensing volumes.

The adjusted check groups observations by year, month and weekday, then subtracts each group's average temperature and average license count. It correlates those remaining differences. This removes the average level within those calendar groups, allowing hot and cool departures to be compared within a similar time setting. It is deliberately a simple diagnostic. It is not a full demand model and does not estimate what the count would have been under a different weather forecast.

License issue dates are the dates in the Clerk's statistical files. They are not ceremony dates. A couple may obtain a license ahead of its planned celebration, so matching weather to the issue date cannot test weather at the ceremony. The 2022 file stops on 22 December; its missing final days are excluded, rather than being filled with zero licenses. The analysis also leaves any missing temperature day outside the matched comparison.

A weak simple association does not establish that weather is irrelevant to every couple. The source cannot observe a trip moved to another day, a ceremony held indoors or a venue chosen for shade. It also does not contain individual plans made before a forecast was available. Those questions need different evidence. The result here is narrower: these matched administrative and weather dates do not show a clear linear association after the stated calendar adjustment.

For your own plans, the historical daily count is not a weather-safety recommendation or a promise about waiting times. The license calendar lets you explore the recorded range for a particular month and day. The license guide follows the Clerk's office requirements and hours. Those are separate questions from choosing the conditions for an outdoor ceremony, transport or time outside.

The station file and data dictionary retain the publisher's measurement and quality flags. Keeping those references makes the join reproducible when the data is refreshed. The published output contains temperature-band averages and the summary comparison, with no locality-by-exact-day demographic table.

NOAA asks users to credit its materials and not imply endorsement. The source retains its own terms, while this site's calculated summaries use the site license. Read the method page for the statistical-file defects and the definitions shared across the site. A future source correction or another model can change a numerical summary, so the conclusion stays tied to this checked file set and the adjustment described here.

The highest temperature-band average is 241.16 daily licenses in the 30 to below 35 C band. The hottest band averages 226.19 across 1,078 covered dates. The chart is therefore not a steadily rising heat ladder, and the calendar-adjusted correlation is weaker than the raw correlation. These are descriptions of the calculation, without an assertion that one temperature band caused couples to apply or stay away.

The cool band contains 1,991 matched dates and 396,237 licenses. The 20 to below 30 C band contains 1,897 dates and 440,181 licenses. Each band average divides its license total by its covered dates.

Official weather references: GHCN station list, airport daily observations, and NOAA reuse guidance.