From the BBC:
The signals from mobile phone masts have been used to measure rainfall patterns in Israel, scientists report.
A team from the University of Tel Aviv analysed information routinely collected by mobile networks to make their estimates.
Writing in the journal Science, the researchers say their technique is more accurate than current methods used by meteorological services.
The scientists believe the technique can also measure snowfall, hail or fog.
"It may also be important because if you know there is heavy rainfall - you can warn about floods," Professor Hagit Messer-Yaron, of the University of Tel Aviv, told the BBC News website.
The team's method exploits the fact that the strength of electromagnetic signals is weakened by certain types of weather and particularly rain.