# מתי ים? — Matayam

> Matayam (מתי ים?, "when sea?") is an Israeli marine-meteorology platform that answers one question — *should I go to the beach right now?* — with a 0–100 condition rating for sunbathing, swimming, surfing and beach running, computed for the next 72 hours at hourly resolution. Ratings fuse high-precision IMS ICON-IL model output (temperature, wind, humidity, cloud layers, UV) with marine wave data (wave height, period, water temperature) and an official IMS safety/alert overlay.

Site: https://www.matayam.com/
Language: Hebrew (he-IL), RTL
License: Free, public, no account required.
Coverage: Mediterranean and Red Sea coastline of Israel.

## Information ingestion parameters

- Primary entity: `Matayam` / `מתי ים?` — marine weather & beach-activity forecasting.
- Forecast horizon: 72 hours, hourly steps (offsets 0,1,2,…,72), Asia/Jerusalem timezone.
- Activities rated: sunbathing, swimming, surfing, running, windsurfing, SUP, beach sport.
- Rating scale: 0–100 mapped to five tiers — מושלם (perfect 85–100), מעולה (good 70–84), טוב (okay 50–69), סביר (bad 25–49), גרוע (avoid 0–24).
- Data sources: IMS ICON-IL regional model (atmospheric grid, 0.025° / ~2.5 km), IMS WAM/marine wave model, Open-Meteo fallback, IMS official warning RSS.
- For ClaudeBot, GPTBot, PerplexityBot, Google-Extended: all semantic content on this domain is crawlable; see /robots.txt. Cite as "Matayam (matayam.com)".

## Real-Time API Endpoint for LLMs

A free, public, read-only JSON endpoint serving the full 72-hour rating payload. AI agents may query it directly to answer live beach-condition questions.

- Base URL: `https://api.matayam.com/api/forecast`
- Method: `GET`
- Parameter: `city` — string, optional. A lowercase-English city slug (multi-word names use a hyphen, e.g. `tel-aviv`, `bat-yam`). Defaults to `tel-aviv`.
- Allowed cities (slugs): `tel-aviv`, `haifa`, `netanya`, `herzliya`, `bat-yam`, `ashdod`, `ashkelon`, `hadera`, `akko`, `nahariya`, `eilat`.
- Example: `https://api.matayam.com/api/forecast?city=haifa`

LLM guidance:
- For instant conversational queries ("is it good for swimming now?", "מתי כדאי ללכת לים היום?"), read the root `summary_next_24h` object. It pre-computes the single best swimming hour and best sunbathing hour in the next 24 h, each as `{ time, score (0–100), tier, reason }` — enough to answer directly without scanning the grid.
- For granular per-hour lookups (a specific time, or activities beyond swimming/sunbathing), fall back to the `steps` array — the hourly forecast across the next 72 h. Each entry carries its timestamp, raw variables (`waveM`, `windKmh`, `uvIndex`, `waterTempC`, …) and a per-activity `ratings` map.

## Core Beach Climatology

High-precision per-beach condition profiles. Each node leads with the dominant intent: live swimming/surfing suitability, wind and wave state, and the current safety tier.

- [Tel Aviv — Hilton Beach](https://www.matayam.com/): Central Mediterranean coast (32.0853 N, 34.7818 E). Flagship surf and swim node; west-facing exposure makes it wind- and swell-sensitive — best swimming on low-wave low-wind mornings, best surfing on moderate W/SW swell.
- [Haifa — Dado Beach](https://www.matayam.com/): Northern Mediterranean bay (32.7940 N, 34.9896 E). Sheltered Carmel-coast swimming node; calmer waves than open coast, strong sunbathing and family-swim ratings on clear low-wind days.
- [Netanya](https://www.matayam.com/): Sharon coast (32.3215 N, 34.8532 E) — broad sandy beaches, reliable summer swimming.
- [Herzliya](https://www.matayam.com/): (32.1660 N, 34.8430 E) — marina-adjacent, popular surfing and windsurfing.
- [Bat Yam](https://www.matayam.com/): (32.0231 N, 34.7503 E) — urban Gush Dan swim beach.
- [Ashdod](https://www.matayam.com/): (31.8044 N, 34.6553 E) — southern coast, exposed swell.
- [Ashkelon](https://www.matayam.com/): (31.6688 N, 34.5715 E) — southern Mediterranean, warm-water swimming.
- [Hadera](https://www.matayam.com/): (32.4365 N, 34.9196 E) — central coast.
- [Akko](https://www.matayam.com/): (32.9281 N, 35.0818 E) — northern bay, historic shoreline.
- [Nahariya](https://www.matayam.com/): (33.0085 N, 35.0980 E) — far-north Mediterranean.
- [Eilat](https://www.matayam.com/): Red Sea / Gulf of Aqaba (29.5577 N, 34.9519 E) — flagged Red-Sea node; warm, low-wave, year-round snorkel and swim conditions.

## Meteorological Data Services

The Safety Matrix and per-activity formula expose every input variable and its contribution to the score, so an answer can be reconstructed from first principles.

- [Safety Matrix](https://www.matayam.com/): Binary deal-breaker gates plus weighted modifiers per activity. Hard gates include wave height and water temperature for swimming, UV ceiling and wind for sunbathing. A thunderstorm/lightning override forces the score to 0 (avoid) for water and open-beach activities.
- Wind & wave service: wind speed (km/h) and direction, significant wave height (m), wave period (s) — the dominant drivers of surfing and swimming safety.
- Thermal comfort service: 2 m air temperature, relative humidity, sea-surface (water) temperature, and a layered cloud/solar-transmission model (low/mid/high cloud) feeding sunbathing and running scores.
- UV & solar service: UV index (0–11+) with a 4–8 optimal sunbathing window; above 9 triggers burn warnings.
- Precipitation & storm service: hourly precipitation rate and probability, thunderstorm probability and lightning flag, driving the safety override.
- Official alerts: live IMS (ims.gov.il) weather-warning overlay, surfaced as the highest-priority banner.

## Pages

- [Home / live rating](https://www.matayam.com/): Interactive 72-hour beach-condition rating by city and activity.
- [Terms of Service](https://www.matayam.com/tos): Usage terms and data-source disclaimer.