That is if the general air temperature is between 10° C and 32° C you should be safe. There are other factors that might determine the outcome like wind and humidity along with water temp have an effect on pouring concrete in less than favorable conditions.
Temperatures below 0° C should be left until warmer weather or best recommendation would be to hire a pro. Concrete sets slower in colder temperatures so the key to getting it right is to make sure the concrete sets fast.
Here is a cold weather tip to get your concrete set right, use hot water. You could always use a fast setting concrete to pour you your slab but if you really want it done right call someone who does it for a living.