Freezing temperatures hit Valley: How rare is cold blast like this?

A major winter blast is hitting Arizona leaving behind the coldest temperatures we have seen so far this season. But just how rare is it to see freezes in Phoenix for several nights in a row?

While freezing temperatures can be fairly common in the outlying areas of the Valley, metro Phoenix tends to stay several degrees warmer as the miles of concrete and large buildings trap more daytime heat overnight.

Due to that urbanization, seeing long stretches of freezing temperatures in Phoenix has become pretty rare.

In fact, in the last 30 years the longest stretch of days with a freezing low temperature (32 degrees or below) is just four. That happened back in December of 1988, and as of Tuesday morning, we have matched that with this cold snap.

Check out this week's 7-day forecast .

To put things into perspective on just how much the heat island effect has changed things, the longest stretch of subfreezing temperatures ever on record in Phoenix is 14 days. That happened back in December of 1916.

Even as recent as January of 1967, we had a subfreezing stretch of 12 days in a row.