I went to Cancun in Mexico last October for a week and the sun was fantastic (80 degrees) and the total rainfall for the week was for about and hour (and much of that at night).
If it rained during the day it lasted a couple of minutes and then the sun came out. Most people did not even bother to get out the pool.
There are some great all inclusive resorts along the Cancun coast.
We stayed at the Grand Palladium.
It was all inclusive, a HUGE site with loads of nature and wild animals. All the food and drink and entertainment was included and we hardly spent a penny during the week.
There were about 15 restaurants and about 30 bars on the site, some of the bars were open 24 hours.
If you did a holiday in Mexico Cancun area you would not regret it.
Last year my daughter and I took a 21 day rail journey across America from NYC to Washington (absolutely fabulous), Chicago, Denver, the Rockies, San Juan Mountains (beautiful), Monument Valley, Grand Canyon, Flagstaff, LA and San Francisco. It was an organised rail tour. We had sun every single day and I was wearing flip flops and still have the tan.
have to say - I have been to Mexico a few times but never that latein the year. I am soooooo tempted. Can't go to Tunisia as her son (my ex) is going there and I don;t want it to look like I'm a stalker :-) Also love the Algarve but haven't been there for 30 years - will give that a look if they still do Brandymel :-)
If you're interested in history at all, a Nile cruise is a must. Just the cruise is most enjoyable, with an ever changing backdrop. The visits to the temples, Valley of the Kings etc are the icing on the cake.