In this weather it isnt a problem, when i was younger i used to clean cars around my local town, got throught about 20 a week, what i find when its really sunny, if you was one section of the car at a time, say the drivers side, then rinse this off wiht the hose, then move onot the next section, and when you rinse this section off go back over and rinse the previoius section, this way it doenst ever fully dry. If ti does before you chamois it just wet the area first, then when you chamois it over it removes the streaks. You shoudl never wash the car in direct sunlight.
In the winter i usually use 2 buckets of water, after ive finished the 1st one i hose the car all over, and again when ive finsihed the 2nd one, now the car is really wet and you shoudl be able to leather it easily.
Do you have a new chamios, sometimes if its old it takes ages to pick up the water, buy a new one, they are only a few quid.