Organizing an international high school reunion and looking for a visa-friendly, enjoyable, and affordable destination

While I'm not a seer and cannot predict the exact situation in 2017, my vote would be for Georgia. Let's take a look at your criteria:

• Safe

Georgia is generally an extremely safe country, despite all the international attention towards the conflict with Russia. It's ranked at #112 in the list of countries by intentional homicide rate and most travelers would confirm it's not a dangerous place.

• Visa-friendly

Citizens of almost every country in the world can visit Georgia visa free or get an E-Visa online.

• Affordable to get to

Georgia's airports welcome dozens of regular and low-budget airlines, including regular flights to the hubs in Istanbul and Dubai. On average, it shouldn't be more expensive for your guests to get there.

• Affordable to stay at

Tbilisi is cheaper than Bangkok and definitely cheaper than any other European country.

• Enjoyable climate in August

It's very hot in the capital, sunny and warm on the seaside, and sunny and cool in the mountains. You can host your event in three different sub-climates within the same country!

A few options:

1. Asia: Honk Kong or Singapore: very safe, visa friendly, more on the expensive side, hot as hell in August, to do: mostly urban: shopping/some culture
2. Asia: Bangkok: reasonably safe, visa friendly, much cheaper than HKG or SIN (but also less clean), hot as hell in August, to do: lots of shopping/food/temples, resort towns fairly close by.
3. Europe: Berlin: very safe, visa okay for most countries, much cheaper than London or Paris, really nice in August, to do: party all night long, street foods, beer garden, excellent museums, live music etc.
4. North America: many options but visa can be a problem depending on country. Most places will be fairly hot and humid in August, I'd look at Vancouver.
5. Australia/New Zealand: probably too cold in August
6. Some resort Island (Aruba, Maledives, Fiji, Bahamas). Warrants a second look. Typically easy to get to and visa friendly (to support tourism). However it'll be high season in August (summer vacation in the Northern hemisphere) or insanely hot or both.