A similar thing happened to us although they didnt all fail on the same day.
As the bulbs went in our old outside lights we swapped them in a single weekend for new LEDs, but they all lasted about 2/3 months.
My elecrician friend says that they we need at last IP65 for protection against the rain. IP 44 is shower proof and with this recent wet weather i think it is possible for yours to have been ruined in a single downpour. If your electrician supplied them, then complain. But if you bought them from B&Q like we did, you can bet your life they were poorly made in the far east. Try reading some reviews of your make and model. They shouldnt be selling them, everyone has same problem and they are rubbish.
We're just bought another set online that are a bit more expensive, IP65 and made in Europe. With good reviews, fingers crossed.