Hi,
I have been to Borneo twice,both times end of march -mid april.The weather has been brilliant both times,very hot and sunny everyday,with the occasional rain late afternoon.
We climbed the mountain[kinabalu],and march is said to be the best month to do this,we certainly had a good climb,and a fantastic sunrise,very clear.
Borneo ,is my favourite place i have visited so far,and i have travelled alot.There is so much to see and do there,especially of you like ,nature,adventure,hiking,and some beautiful islands.I went to sabah both times,and stayed at the Tanjung aru[shangri-la group] an excellant hotel.
Have fun
suzi

We also went to Sabah in mid April, staying at the Shangri-la Rasa Ria and the weather was wonderful. Check out the blue skies and fabulous sunsets in my snaps .

We went end of aug/beginning sept, lovely weather but thunderstorms late afternoon!
Stayed at the Rasa Ria, it was wonderful!!!