The temperature in my area is around 45c, which is too hot. Is it good to feed pellets in these weather conditions?
The good old Budgie can cope with way higher temperatures than 45c. The are out of central Australia after all. They can cope with temperatures as high as 85c before the heat kills them. Budgies are tough little birds and can survive some harsh treatment. They can survive up to 6 weeks without water in the wild. Not that I would in any way suggest that they be exposed to these conditions. Lower temperatures are a little harder on them though.
Pellets are dry so temperature has no impact on them. Moisture on the other hand is a problem. Pellets are a better choice than seed as they are much lower in fat. In the wild a bird will burn a huge amount of energy so seeds are great. Lots of energy in seeds for a bird that flies huge distances. Not so good for a bird in a cage. Pellets are also supposed to be a balanced diet with all the vitamins and minerals your bird needs. Like with any pet food this is not always the case. Research any brand before you give it to your birds.
Pellets should be the primary source of food for your bird, depending on species, with fresh veg and fruit. Because pellets have added vitamins and minerals it is very important to research and find a good quality pellet. Just like with humans too many vitamins and minerals in their diet can prove toxic and potentially fatal. Personally I think about 60% pellet, 20 - 30% fruit and veg and the remaining 10 - 20% a mixture of seeds/nuts/grains etc.
One thing that you might like to try is green seed for you birds. Take a tray of potting mix and sprinkle some of your birds seed over it. Water and put somewhere birds can't get to it. Once it has grown enough to start producing seed heads offer it to your birds. Most of my birds love to have green seed to chew on.