Colorado history

Monday, August 24, 2026

A Front Range cold front behaves like a trap door, Spain admits Mexico is a country, and the Democratic convention week grows a few landspouts.

Denver drops 53 degrees between lunch and midnight

1910 · Denver

On Aug. 24, 1910, a dry cold front slammed Denver. The temperature fell from 93 at 3 p.m. to 40 by midnight — tying the lowest August reading the city has on the books. Northeast winds held at 44 mph.

August on the Front Range is supposed to argue with itself, not surrender.

This front did not bring a useful rain. It brought a change of season in nine hours. From mid-afternoon to midnight the mercury dropped 53 degrees. The official August low of 40 degrees would be matched the next two mornings, and it still sits on the record with Aug. 22, 1904. Out on the northeastern plains the same air put temperatures below freezing while the calendar insisted it was summer.

People who packed for a 93-degree Tuesday learned the local rule the hard way: if a Front Range forecast mentions a cold front, believe the second number, not the first.

Sources: National Weather Service notes via ThorntonWeather · Westword — Denver weather history

Spain signs away an empire. Southern Colorado changes letterhead.

1821 · Córdoba, Veracruz / future southern Colorado

On Aug. 24, 1821, Spain signed the Treaty of Córdoba recognizing Mexican independence. The land that is now southern and western Colorado — Taos trails, the San Luis Valley, the upper Rio Grande — stopped being New Spain and became Mexico.

Colorado’s American origin story likes to start with gold and a railroad. A lot of the state had a previous government.

The Adams-Onís line of 1819 had already given Spain (and then Mexico) the country south of the Arkansas. Bent’s Fort would sit on that border. The San Luis Valley’s later land grants were Mexican paperwork. When Mexico City took the keys on this date, the people moving sheep, wool, and families along the Rio Grande were not waiting for Denver to be invented.

The Mexican-American War and the 1848 treaty would move the line again. Aug. 24 is the quieter hinge: an empire exits, a republic inherits the Sangre de Cristos, and the future state is already a borderland.

Sources: Wikipedia — Treaty of Córdoba · Wikipedia — Colorado

Convention week grows a few landspouts southeast of town

2008 · Elbert County / southeast metro

On Aug. 24, 2008, as Denver finished setting up for the Democratic National Convention, landspout tornadoes spun up along a boundary southeast of the metro. Northwest Elbert County reported minor damage. The delegates still arrived.

A landspout is the plains’ budget tornado: no supercell required, just a boundary, some spin, and a cloud that decides to reach down. Several of them developed southeast of Denver on this Sunday while the city was hanging banners and testing magnetometers.

Damage was minor. The convention opened the next day. By Thursday night 84,000 people were sitting in a football stadium listening to a nomination speech, which is a useful reminder that Colorado can stage national television and still have weather with its own agenda.

If you were in Elbert County that afternoon, you got the local version of the week. If you were downtown, you got the other one.

Sources: National Weather Service notes via ThorntonWeather