From May to November, Panama's risk to a boat isn't one big storm. It's rain, lightning, squalls and humidity, almost every day for seven months. Prepare once in April: covers that shed water, clear drains, bilge pumps and batteries you trust, ventilation against mould and a lightning routine. Then check the boat weekly until December.
Why Panama needs a rainy-season plan, not a hurricane plan
In Florida, the season plan is a hurricane plan: where the boat goes, how it's tied or hauled, and who moves it when a named storm is coming. It's built around one event you can see coming days ahead.
Panama lies south of the usual hurricane tracks and has had no hurricane landfalls. The closest call was Hurricane Otto in November 2016. It passed about 75 nm north-north-east of Colón and came ashore in southern Nicaragua, yet the NHC report counts eight deaths in Panama from landslides, a falling tree and a flooded river. What Panama has instead is a rainy season from roughly May to November, with September and October usually the wettest months. Squalls build after midday, and lightning is the real hazard on both coasts. IMHPA notes that the start moves from year to year: for 2026 it forecast a start two to three weeks later than usual, from late April in Chiriquí to early June in Panamá Oeste. On the Caribbean side (Bocas del Toro, Colón and Guna Yala) it rains often for much of the year, so keep the routine running there year-round. More on the seasons is in Panama boating seasons.
That changes the plan. You aren't preparing for one storm. You're preparing for heavy rain on an unattended boat, gusts at a mooring, lightning near electronics and humidity inside the cabin, day after day. Watch the US National Hurricane Center outlooks from June to November anyway, especially on the Caribbean side and in Bocas del Toro.
Covers, drains and bilge pumps
A tropical downpour can drop more water into an open boat in an hour than a small bilge pump can move. Boats sink at the dock this way.
- Covers: fit them tight and pitched so water runs off. A sagging cover collects a pool, then tears or dumps it into the cockpit. Check the stitching and snaps before May. UV rots thread long before it rots canvas.
- Drains: clear cockpit scuppers, deck drains and anchor-locker drains of leaves and dirt. Check that drain hoses and their clamps are sound below the waterline.
- Leaks: reseal hatches, deck fittings and window frames that weep. Rain finds every gap, and leaks feed mould.
- Bilge pumps: test the float switch and the pump, clean the bilge, and fit a second, larger pump with its own float switch if the boat is open. Bilge pumps and rainy-season flooding have their own guide: bilge pumps and rain.
- Batteries: a pump needs power. Keep the bilge battery charged from shore power or a solar panel, and check it after a wet week.
Mould and humidity
Humidity stays high through the rainy season, and a closed boat becomes a mould farm in weeks. Keep air moving:
- Run a dehumidifier or the air conditioning on shore power if the marina allows it unattended. Ask the marina first.
- Fit solar vents or passive vents that let air in and keep rain out.
- Leave lockers, drawers and the head door open, and stand cushions on edge.
- Take sails, life jackets, towels and spare clothes home or store them dry.
- Wipe surfaces with a mild vinegar solution before mould takes hold, and clean the air-conditioning filters monthly.
Mould on cushions and headliners is a resale problem as well as a smell. Note when you cleaned and what you treated in your maintenance records.
A lightning routine
Lightning is the main threat to electronics in Panama's rainy season. Before May:
- Check that the boat's bonding and any lightning protection system are intact.
- When you leave the boat, switch off the battery switches and unplug antenna leads from expensive electronics where you can.
- Keep a handheld VHF and GPS aboard as a backup.
- On the water, plan to be in port or at anchor by mid-afternoon.
The full detail is in lightning protection for boats in Panama. What to do when a storm catches you underway is in lightning and squalls.
Lines, moorings and debris
A squall can gust far above the forecast for twenty minutes or so, and the wind shifts as it passes. Before the season, double the dock lines on the windward side, add chafe guards where lines cross fairleads, and check the condition of any mooring you use. Heavy rain also flushes logs and branches out of the rivers. After a big storm, run slower until you've seen what is floating, and check that intakes and strainers are clear.
A month-by-month calendar
| When | What to do |
|---|---|
| March–April | Haul out and paint the bottom, reseal leaks, service covers, test pumps, check bonding and lightning gear |
| May–August | Weekly check: bilge, battery voltage, covers, lines and mould. Clean the bottom more often. |
| September–October | The wettest months. Check after every heavy rain, and watch IMHPA and SINAPROC alerts. |
| November–December | Dry the boat out, treat mould, inspect wiring and electronics, and log any lightning damage |
If you're away, put one person in charge of these checks in writing: a marina caretaker or a captain you trust. Use the rainy-season prep checklist to hand over the tasks.
Your practical starting checklist
- In April, reseal leaks, refit covers so they shed water, and clear every drain.
- Test the bilge pumps and float switches, and add a second pump on an open boat.
- Keep the bilge battery charged from shore power or solar.
- Set up ventilation or a dehumidifier, and take soft gear home.
- Check bonding, and switch off and unplug electronics when you leave the boat.
- Name one person to check the boat every week from May to November.
Frequently asked questions
Do I need a hurricane plan for my boat in Panama?
Not in the Florida sense. Panama has had no hurricane landfalls, but you need a rainy-season plan for daily rain, squalls and lightning. Watch NHC outlooks from June to November.
When is the rainy season in Panama?
Roughly May to November, with September and October usually the wettest. Squalls and lightning build in the afternoon.
How do I stop mould on my boat in Panama?
Keep air moving with vents, a dehumidifier or air conditioning, leave lockers open, take soft gear home and wipe surfaces before mould takes hold.
Can rain sink a boat at the dock?
Yes. Heavy tropical rain can overwhelm a small bilge pump, especially if drains are blocked or the battery is flat. Clear drains and keep pumps and batteries tested.
En español: preparar la lancha para la temporada lluviosa
En Panamá la temporada lluviosa va de mayo a noviembre. El riesgo no es un huracán, sino la lluvia, los rayos y la humedad de todos los días. Antes de mayo: selle filtraciones, tense los forros para que escurran, limpie los drenajes, pruebe las bombas de achique y mantenga cargada la batería. Ventile la cabina contra el moho y desconecte los equipos electrónicos al dejar la lancha. Siga los avisos del IMHPA y del SINAPROC.
The next question to answer
The full maintenance picture for heat, humidity and growth. Read Boat maintenance in Panama's tropics.
A printable list to work through or hand to a caretaker. Read Rainy-season prep checklist.
Sizing, float switches and power. Read Bilge pumps and rainy-season flooding.
Same topic in Florida: coming from the US? Compare Building a Florida Boat Hurricane Plan.
Official resources
Use the relevant Panamanian authority for current requirements and fees. These resources are the next place to check; a practical recommendation is not an agency determination.
- TVN (secondary): IMHPA lightning data and SINAPROC advice, Sept 2025 ↗
- Practical Sailor (secondary): Lightning protection 101 ↗
- NHC Tropical Cyclone Report: Hurricane Otto (AL162016) ↗
- La Prensa (secondary): IMHPA 2026 rainy-season start dates by region ↗