Hi Madison,
I'm so jealous that you and your husband are planning to go to Thailand. My husband & I went around mid April for 2 weeks. It was the best trip we've ever had. The diving was amazing. There was slightly more current than I would have liked but it was not problematic type of current. It was more like drift diving, which I am not the biggest fan of since you move past everything so quickly it's difficult to see the smaller things, but fantastic for the larger animals of the ocean. Viz was ok but not the best I've seen. Florida Keys still offers the best vis in my opinion. But then again, it's much shallower diving. However the type of animal and plant life that you see in Thailand is incredible. As small as ghost pipe fishes, nudibranchs, harlequin shrimps, clown fishes, anenomes, whale sharks, baby whale sharks, manta rays, more clown fishes (all types). What more can I say, lots of life.
Ok I'm getting carried away.... just so excited for you. But to answer your question, I think Eagle said it the best...check out the gov site. But the way I see it, I'm from NY and you're from NJ. We probably live in one of the considered dangerous threat condition areas. So, seems like other places might be safer to me.
When we were in Thailand in April, everyone seemed friendly enough. In other words, there really wasn't any hostilities aimed at us. They seemed to smile all the time and most of the places we went to had English speaking Thais. Then again, we were in Phuket which is pretty much a tourist trap.
In April, the weather started to get really hot. I hear from others that it gets even hotter in May, June, July. The heat is pretty bad but since we were on a 10 day liveaboard on the Viking Liveaboard (Scandinavian Divers), it was fine. We spent 3 days on shore before and after the liveaboard. When we compare the heat to out on the ocean, it's SOSO much cooler on the ocean.
The liveaboard is the best way to go diving there, the waters were calm during April. And it was so easy just to not have to worry about anything. We did the 10 day Expedition and it was amazing. We went to all the areas around Phi Phi Islands (vis was not great) and the Similan Islands (amazing vis). My typical day was wake up in the morning, grab some coffee or juice and toast, change into bathing suit, grab a tank, go for a dive, come back have an omlete made special for you. Take a break: either a nap, read, or hop on the dingy for a ride to one of the nearby secluded beaches to do some exploring, come back to boat, go for 2nd dive, come up and have lunch while looking at breath-taking scenery, take break: nap, read, etc...., go for 3rd dive sometime around 4 o'clock, come up, take break, have maybe a night dive (but most people are too tired) then dinner time, and that's the end of one fantastic day...
I felt that being on the liveaboard made me feel alot safer than on land in some ways since you are away from the crowds and if any, threats....even though there were none.
Hope this is helpful to you. Sorry about my rambling on...I'm just so excited for you two. Keep us posted on if you go. Take care.