It wasn’t just unusually hot the past few days, it was hotter than anything we’ve ever recorded for May 11-12.
Low and high temperatures set heat records in the 4 main cities of the region. Starting Wednesday, record lows were set in Iowa City and Cedar Rapids, by a mere squeak, while Dubuque tied the long-standing record dating back to 1881.
Highs hit the low and mid-90s on Wednesday afternoon, shattering old records in Waterloo and Iowa City and setting new ones in Cedar Rapids and Dubuque. These were 100-year records in Waterloo and Cedar Rapids, and a 143-year record in Dubuque.
Thursday morning, same thing. Hot bass records were erased and some old records from Waterloo and Dubuque bit the dust.
Another hot Thursday afternoon again brought highs into the low and mid 90s, setting new records for all 4. These were 100+ year old records for all but Iowa City.
This link has more registration information for smaller sites in northeast Iowa.
If you’re wondering why we say Iowa City has limited records, it’s because it’s not an official climate site. There have been multiple sensors in Iowa City for many, many years, but the data has not been aggregated and checked for quality. The main problem is reporting deadlines.
Iowa City records that you might see elsewhere on social media are usually pulled from an Iowa City COOP site. The problem is that the reporting time for some of these COOP stations is not midnight to midnight, but most likely around 7am. This means that highs, lows, precipitation and snowfall can actually be offset by one day and not match other surrounding observations, making them essentially useless when it comes to recording calendar days.
Therefore, we are showing records from Iowa City Airport. The Iowa City Airport sensor is a midnight-to-midnight sensor and maintains reliable climate data on calendar days. The problem is that it only recorded temperature data from 1948 to May 1953, and then again from July 1996 to today. Therefore, you don’t have a clear idea of the records in Iowa City and that’s why the records we show are often far away and newer than the records in the other 3 cities.