February is a very good time for safari in the Masai Mara, but also very different to the experience in June and July.
It's hotter and drier in February and generally there are fewer other tourists. There will still be plenty of zebra and wildebeest around but these are the non-migrating resident herds, so they don't form the massive iconic herds that you might see on TV.
July is good because the migrant wildebeest are all normally in the Mara by then, but its also absolute peak high season so can be busy and expensive. June is perhaps my overall favourite month. Everything is green after the rains and it's nice and cool with far fewer tourists than July, but the first migrant wildebeest might start to arrive (it all depends on rains and the state of the grass).
In short, all three months are excellent but each is different so it might be best to go with whatever just suits your timings better.
