Latest Weather Forecast For Tucson Heading Into Mother’s Day Weekend: See Details

TUCSON, AZ — Tucson is getting a brief gift of mild weather to open the week, but do not let it fool you. The heat is on its way, and it could arrive just in time for Mother's Day.

Temperatures today are running nearly 10 degrees below normal, a lingering effect of a Pacific weather system that moved through Tuesday.

Winds will also be much calmer than yesterday, staying mostly under 12 mph with only a few afternoon gusts. Enjoy it while it lasts.

From here, the warmup is swift and significant. A high pressure ridge building across the western United States is expected to take over as the dominant weather feature, pushing Tucson temperatures 6 to 10 degrees above normal by the weekend.

That puts Mother's Day Sunday in the running for triple digits, with the National Weather Service placing the chance of hitting 100 degrees at Tucson International Airport at 25 percent.

Forecasters note that temperatures within the city itself tend to run even hotter.

The real heat arrives Monday and Tuesday. The ridge is forecast to peak early next week, with the chance of topping 100 degrees rising to 75 percent Monday and 60 percent Tuesday.

Desert highs across the broader region could exceed 100 degrees during those days, with some areas pushing higher.

The drying trend accompanying the heat is also raising some fire weather concerns as the week progresses. Humidity is expected to remain relatively manageable today, staying above 15 percent in desert areas and above 20 percent in the mountains.

But by the weekend, minimum relative humidity in desert locations is forecast to drop into the single digits, with mountain areas falling below 15 percent.

Winds are expected to remain generally light, which should limit the most critical fire weather conditions, but the combination of extreme heat and very low humidity will bear watching.

Skies will be clear through the period, so if you are planning a Mother's Day celebration outdoors, morning hours are your best bet. By afternoon Sunday, Tucson will already be feeling the leading edge of what could be a punishing stretch of early summer heat.