Seemed stable the last time I used it.
Chronoed 172 with a ambient temp of 80 degF, 29 in on baro, humidity 30% (Norco, CA right befoe 2009 IPSC Nationals)
Chronoed 170 with a ambient temp of 58 degF, 30 in on baro, humidity 75% (2009 IPSC Nationals. Circleville, OH)
Unless your temperature swings are really big I don't think you'll have to worry.