I have a hard time running when it rains too...I solved it by throwing money at it and bought a treadmill. My running consistency and milage increased considerably, it does take up a lot of space though.
It's so weird living in the tropics, because it's never really cold and by right one should be fine running at any time. But it's still so easy to catch a cold because the humidity just amplifies any temperature difference.
So yeah, totally feel you!