The second storm in a week hit Britain on Saturday, prompting flooding alerts for many parts of the country and disrupting flights and train services just as many schools start their half-term holidays.
The heavy rain and strong winds from Storm Dennis hit barely a week after Storm Ciara caused disruption to transport, flooded homes and left thousands without electricity.
EasyJet has warned of "significant disruption" to its operations with multiple flights cancelled into Gatwick Airport while Luton Airport was advising passengers to check with their airlines before setting off from home.
A total of 30 warnings were in place in England, meaning flooding was expected, and 238 alerts cautioning that flooding is possible, according to the Environment Agency.
A total of 75 military personnel were helping to build barriers and repair flood defences in Yorkshire, northern England, where the ground was already saturated from last week's rain.
"The government won't hesitate to use all means at its disposal to mitigate the effects of Storm Dennis," said defence minister Ben Wallace.