hottest

March 2017 – Hottest Ever in Tucson?

Front page news in the print version of Arizona Daily Star on April 4th proclaimed “March here was hottest on record.” (See online version) That may be true but the headline is also misleading because apparently the “record” refers to the weather station at Tucson International Airport which starts in the mid 1940s. Hot weather in the early 1900s is ignored.

The following graphs come from the National Oceanic and Atmospheric Administration (NOAA) “climate at a glance” page. (Note: NOAA data does not yet include any 2017 measurements.) The National Weather Service is part of NOAA.

Here is the average March temperature for all of Arizona:

Here is the average March temperature for Southeastern Arizona:

Here are the plots for Tucson March average temperatures and maximum temperatures:

 

 

 

 

 

I assume that the truncation of data prior to about 1945 reflects the start of the official temperature record from a weather station at the Tucson International Airport. Other weather stations in Tucson, such as the one on the University of Arizona campus, have been ignored. BTW, the UofA weather station was established in 1891. So, the question is whether or not the “hottest on record” was in fact, the hottest.

For additional perspective, see average and maximum Arizona temperatures for each month here.

Tucson is subject to warming from the urban heat island effect. All the asphalt and concrete absorb energy during the day and release it at night. Also the Tucson weather stations are sited near asphalt and concrete which tend to make the readings higher than they would be in properly sited stations. To demonstrate this, compare Tucson temperatures with Tombstone. Tucson temperatures show a steady rise while Tombstone, shows that after warming from the “little ice age” in the late 1800s, temperatures remain relatively constant.

 

Finally we have a plot of global atmospheric temperatures as measured by satellites. These data include March, 2017 and show that global temperatures are cooling from the heat of our recent El Nino.

For some additional perspective, see 2014 was the third or sixth or 8000th warmest year The material in that article applies to this year also.