Four Cities, Page 3


San Antonio-24 hour day.gif (9914 bytes)

Nearly 925 miles south of Grand Rapids, San Antonio is the southernmost of the four cities. It receives both southern heat and Gulf humidity. From the standpoint of heat stress, this is not a very favorable August 4th venue. The overnight cooling is inadequate, and on average only 2 hours out of 24 show a heat index of less than 80F. Daytime heating is substantial, with the result that only 5 a.m. and 6 a.m. fall outside the High Risk Zone. With minimal microclimate heating, such as from artificial turf or a tennis court, temperatures from 11 a.m. to 7 p.m. will fall in the Event Delay Zone. Closer examination of this chart shows that there is "no way out": Even the lowest 30-year heat index values from 11 a.m. to 8 p.m. are in the High Risk Zone.

It must be remembered that many factors besides heat index influence site selection. The creative event organizer can often "schedule around" environmental hazards in such a way that the competitors are not seriously hampered by weather and air quality problems. It is imperative, though, that these factors be recognized as early as possible in the planning process.

Next Page.

[Home]   [The Chart Room]  [The Map Room]  [The Chart Store]   [The Library]
Send mail to with questions or comments about this web site.
Copyright 1998 The Zunis Foundation. Last Modified: April 2, 2009.