By day's end, Phoenix will have gone two straight months without measurable precipitation. The last time Phoenix Sky Harbor Airport received any rain was back on Jan. 31.

Marvin Percha with the National Weather Service in Phoenix said the extended stretch of dryness isn’t that uncommon for the Valley. But this time of the year, it is.

“Having two straight months in a row here in Phoenix is not unusual, but these days months, February and March having none, is rather unusual," said Percha. "In fact, it’s only the third time we’ve had it in a 120 years.”

The last time it happened was 1984. The region normally averages about an inch of rain in February and March. 

Percha said changing weather patterns have made predicting future rainfall even tougher.  

“Given the fact that we’re transitioning from an El Nino regime to a La Ninian, it’s kind of a difficult forecast," he said. "It could go either way, especially considering that we don’t really know the strength of the La Nina, so there’s a lot more uncertainty in the forecast than we’ve had before.”

After an above-average start for rainfall in January, Phoenix is now about 1.5 inches below normal for the year.

Tucson, which saw last saw any rain on March 8, is about 0.7 inches below normal so far in 2016.