Since July is the school holiday time in Vietnam, it is also the peak season for domestic tourism.
Vietnamese often travel with their family or bigger groups, so expect crowd at popular destinations such as Sam Son, Danang, Nha Trang and Vung Tau.
The downside of traveling to Vietnam during this time is that the sun may be overwhelming. Make sure to keep yourself hydrated and avoid being out at noon.
In addition, July in the North can see a few typhoons, which may get trips cancelled. Cruise trips for example are prone to cancellation during bad weather.
If you do trekking in the Northern mountains, take extra precaution to avoid possible landslides.
It is best to plan a relaxing beach escape in July but avoid the weekend if possible. Con Dao Archipelago and Phu Yen are two great places for you to give some serious consideration for your July trip, as the water is calm and they are not yet caught on local tourist radar so far.
Lan Ha Bay and Cat Ba Island are also lovely to visit in July. There are risks of typhoons, but schedule your visit right and you will see the Bay at its purest. The crystal clear sky and sparkling water are most perfect in July.
In case the heat is too overbearing, you are welcomed to make side trips to Sapa, Dalat or Bana Hills. The high altitude guarantees year round cool climates.
Take a stroll around Xuan Huong Lake, a hiking trip to Datanla waterfall (Dalat), a brisk trekking to Ta Phin village (Sapa) or a full day visit to Bana Hills which houses the famous Golden Bridge, you can find July oddly pretty despite the heat and the rain in the lowland.