East Coast Texas to Villahermosa
Mexico's gulf coast is a lot wetter than it's West Coast, both summer and winter. Winters can be cold and wet and summers are always steamy. Best weather is in deep winter, December through February.
Further climate and weather information is available online from:
US Cash or traveler's checks for personal expenses
Personal toilet kit
bath towel, soap, toothbrush, toothpaste, and other favorite or necessary personal toiletries
Canteen or water bottles (1 liter plastic bottles may be purchased locally in Mexico)
a sturdy, reusable laundry bag
Work boots
something like a lightweight hiking boot, tough and well broken in
Recommendations/suggestions:
Work clothes
anything that is cool in high humidity and dries quickly is good
Town/travel clothes
No short-shorts, halter-tops, dirty or ragged clothes for trips to public areas
Tennis/running shoes
Work gloves
cotton or canvas work gloves dry quickly
Leather gloves are good but dry slowly and sometimes mold or mildew
Shower/swimming/sandals/thongs/flip-flops
Hat
something that will protect you from rain and sun that can be stored in your backpack
Swimsuit
Battery-operated fan and batteries
Insect repellent
for skin: Deep Woods Off!™ or Off! Skintastic™ are commonly used - up to about 30%-35% DEET.
for clothing and gear: Permanone™, or repellent containing permethrin
Pocket knife
Pens, pencils, paper, envelopes
for any personal needs
postcards, stamps and aerograms may be purchased locally
A waterproof marker
(e.g., Sharpie) to mark your laundry with your name
Backpack ("day pack")
you will use this in the field, to carry your lunch, water, and any other personal items, such as camera, binoculars, paper products, notebooks, and field tools
waterproof backpack or application of a waterproofing product
Garbage bags
at least six - to pack things in and keep them dry, including covering your day pack
Poncho/rain gear
some like ponchos that can be thrown on over your backpack
others prefer a waterproof rain jacket or rain suit
Medications and supplements
prescriptions/medications and supplements must be in their original pharmacy containers only - these should include the pharmacy label bearing your name (not anyone else's name).
Carrying a copy of your prescription is recommended.
Make sure you have enough for the duration of your stay. Keep in mind that some medications spoil quickly in hot humid climates, so a dessicant from your pharmacy should be included in the bottle with any tablets.
Consider the following: Pepto-Bismol, Imodium, or your favorite anti-diarrhea medication; aspirin, acetaminophen, ibuprofen, naproxen sodium; eye drops, electrolyte solution (Gatorade powder); foot powder, disposable wet-wipes for field and camp, minor first aid kit, allergy medications, antibiotic cream or wash
Earplugs
for swimming or sleeping
Reading material
Snack foods
granola bars, trail mix, anything that does not require heating or refrigeration
Trowel, line level, tape measure
Camera and film (film is expensive in Central America)