Indonesia Vannamei Harvest Calendar: A Buyer’s 12‑Month Guide

When should you book Indonesian vannamei to secure your target counts and price? Here’s a practical, region-by-region harvest calendar with the real signals we use to forecast supply, plus the questions to ask farms so POs land exactly on harvest.

If you buy shrimp, you already know timing beats everything. Indonesia’s vannamei farms don’t harvest on a single national schedule. They follow the weather, tides, stocking habits, and risk tolerance. After years of planning purchases for customers worldwide, this is the calendar and the field signals we trust when we need certainty on size and volume.

The vannamei crop clock in Indonesia

A typical vannamei crop runs 90–150 days from stocking to harvest. Pond turnaround (drying, liming, refilling) adds 10–21 days. Most farms in Java, Sumatra, Sulawesi, Kalimantan and Nusa Tenggara run two full crops per year. Some drier zones squeeze a third short crop.

What the cycle means for size:

80/100 to 60/70 count: 75–100 days. Common during rainy months when farmers shorten cycles to reduce risk.
50/60 to 40/50 count: 100–120 days. The backbone of export programs in stable weather.
30/40 to 20/30 count: 125–150 days. Requires low to moderate density and steady conditions. Limited, and often snapped up early.

In our experience, average daily gain sits around 0.2–0.35 g/day in Indonesia depending on density, feed program and water stability. That’s why weather matters so much. Which brings us to the calendar.

The 12‑month rhythm and how rain shifts size and volume

Indonesia is tropical. Most regions see a wet season roughly November to March and a drier, more stable stretch April to October. Each farm’s micro‑climate matters, but procurement decisions can follow this useful pattern:

January–February: Rainy. More partial harvests and smaller counts (80/100, 70/90, 60/70). Volumes are available but less predictable week to week. Prices can be jumpy.
March–April: Transition. Stability improves. Farms extend crops to 40/50. Booking opens up for May–June harvests.
May–June: Good growing conditions. Strong 50/60 and 40/50 availability. Many buyers line up POs here for consistent programs.
July–September: Peak dry-season harvest. Biggest volumes, best uniformity. This is the window for 30/40 and occasional 20/30 from low-density ponds. Expect tight processing capacity and cold storage congestion during spring tides.
October: Second wave of strong harvests. Some farms push to 30/40 before the heavier rains set in.
November–December: Rains return. More conservative farming. Crops may be shortened. 60/70 dominates and split-harvests are common.

Does the rainy season reduce harvest or just shift sizes?

Mostly it shifts sizes and introduces variability. Rains drop salinity and water temperature, which can slow growth and increase disease pressure. Farms respond by lowering stocking density or shortening the cycle, so you see more 60/70 and 70/90. Volumes don’t vanish, but harvest timing gets less reliable and partial harvests become the norm.

Regional peaks buyers should plan around

You don’t need a province-by-province spreadsheet, but aligning POs to regional rhythms helps a lot.

Java North Coast (Banten, West Java, Central Java, East Java): Stable dry season. Big harvests July–September and again in October. In East Java especially, 30/40 shows up August–October when farmers extend crops.
Lampung & South Sumatra: Early dry-season stocking is popular. Expect strong May–July harvests, then a second push September–October.
South Sulawesi (Pangkep, Pinrang): Peaks August–October with a reliable follow-up in January–February when local rainfall eases. 30/40 availability can be excellent in late dry season.
West & East Nusa Tenggara (Lombok, Sumbawa, Flores): Drier overall. More even supply across the year, with pronounced peaks June–August and October–November. This region helps smooth programs when Java is rain-hit.
Kalimantan (South and East): Similar to Java’s pattern but often a touch later. Expect August–October volume, then rain-driven volatility from November.

Which regions harvest earliest and latest through the year?

Earliest meaningful volumes for the year often come from Lampung and Nusa Tenggara in May–June as conditions stabilize. Latest big-size harvests usually land out of East Java and South Sulawesi in August–October. When the rains intensify in November, Nusa Tenggara often continues offering more stable supply.

When larger counts are most available (20/30 and 30/40)

30/40: Most available mid‑August to mid‑October across Java and South Sulawesi. There’s a smaller pocket in late January to February in regions with lighter rains.
20/30: Limited. Look to low-density ponds in East Java, South Sulawesi and Nusa Tenggara in September–early October. If you want program volume, you’ll need to pre‑book several weeks ahead and accept some split-harvest scheduling.

We’ve found that buyers who make 30/40 their primary spec and keep 40/50 as a backup can maintain continuity year-round. Chasing 20/30 every month often means you’re buying market luck, not a supply plan.

Aligning POs with pond harvest windows

Here’s the practical playbook we use with farms so your PO lands on harvest day, not two weeks after:

Anchor to spring tides. Full and new moons create spring tides roughly every 14–15 days. Many farms harvest on these windows for better pond draining and water exchange. Place POs 4–6 weeks ahead of the spring-tide window you’re targeting, especially in July–October.
Ask for weekly sampling data. Request size distribution, average daily gain (ADG), survival, FCR and a histogram of “count per kg.” You’re looking for improving uniformity and a coefficient of variation under ~12% in the last 2–3 weeks. That’s your harvest-readiness signal.
Insist on pre-harvest PCR and health checks. Within 7–10 days of target harvest, ask for WSSV, EHP and AHPND PCR, plus dawn DO readings and vibrio counts. Healthy ponds keep schedules. Marginal ponds slip.
Secure processing capacity early. During peak months, plants fill fast. We pencil in line time and cold storage 2–3 weeks before harvest. If you want priority, a modest deposit that ties raw material to your spec is worth it.
Build a split-harvest option into the contract. Many farms pull 20–40% early to de-risk before heavy rains. Structure your PO so the first lift covers core needs and the second lift chases your preferred larger count if growth holds.

Need help syncing your program to actual farm windows? We’re happy to overlay farm sampling with your size specs and target delivery dates. If you want us to look at a live pond schedule, just Contact us on whatsapp.

What signs a farm will delay, partial-harvest or split a crop?

ADG slows for two weeks straight and FCR rises above trend. Farmers wait for a better feed conversion day or pull a portion to reset biomass.
A big rain event drops salinity/temperature. Expect a pause or partial harvest within 24–72 hours as the farm stabilizes the pond.
Size distribution widens. When uniformity degrades, farmers often split harvest to capture the top sizes and give smaller animals another 10–14 days.
Molting signals in sampling. Farms may delay 3–5 days to avoid soft-shell losses.
Price optimism. If local spot prices are gaining week over week and biomass is healthy, some farmers will hold a few days. A clear PO and deposit usually locks your turn.

Common mistakes and easy fixes

Booking by calendar, not tide. Tides cluster harvests. If you ignore spring tides, you’ll miss capacity and pay more. Fix: Book 4–6 weeks ahead of the tide you want.
Asking for 30/40 in January everywhere. Some regions can do it. Many won’t. Fix: Blend 30/40 with 40/50 in Q1 and lean on Nusa Tenggara or South Sulawesi if they’re drier.
Zero tolerance for split harvests during rains. You’ll either pay up for scarce uniform size or suffer delays. Fix: Structure POs with a partial lift clause and clear size bands.
No pre-harvest testing. You inherit pond risk blindly. Fix: Make PCR and last-week sampling a condition to harvest.
Ignoring processing bottlenecks. July–October and late-year peaks jam plants and cold stores. Fix: Reserve line time 2–3 weeks ahead and lock glazing, pack style and labeling early.

Where we fit in your plan

As an Indonesian processor-exporter, we coordinate directly with farms across Java, Sumatra, Sulawesi, Kalimantan and Nusa Tenggara. When you need vannamei in a specific count band, we pair pond sampling with guaranteed processing slots. For customers who prefer a single-source program across items, we can balance shrimp weeks with finfish production to keep your containers flowing. Our Frozen Shrimp (Black Tiger, Vannamei & Wild Caught) formats cover HOSO, HLSO and peeled specs in IQF or block. If you’re building mixed seafood programs during shrimp peak months, our finfish line-up can help you keep shelves full while shrimp sizes catch up. Explore options any time in View our products.

Quick takeaways you can use this week

Target 30/40 and 40/50 POs for August–October. Use 40/50 as Q1 fallback.
Place POs 4–6 weeks before your spring-tide harvest window. Reserve plant time 2–3 weeks ahead.
Ask farms for weekly biomass sampling, pre-harvest PCR and size uniformity metrics. That’s how you know the date will stick.
Expect more 60/70 from November to February. Structure split-harvests rather than forcing a single date that may slip.
Watch BMKG rainfall outlooks and ENSO updates. When the wet season starts early, extend lead times and lean on drier regions.

In my experience, the buyers who win on cost and continuity aren’t chasing spot loads. They’re lining POs to the pond’s calendar and leaving just enough flexibility to let biology do its job. Do that, and Indonesian vannamei becomes a dependable part of your program year-round.