Weather Prediction and Probability
Te Matapae Huarere · Reading Forecasts with Confidence
Ngā Whāinga Akoranga · Learning Intentions
- Understand probability as a measure of likelihood (0–1 or 0–100%)
- Interpret weather forecast percentages correctly
- Compare modern meteorological methods with traditional Māori weather knowledge (tohu huarere)
- Collect and analyse data to evaluate the accuracy of weather predictions
Paearu Angitu · Success Criteria
- I can correctly explain what "70% chance of rain" actually means
- I can place events on a probability scale from impossible (0%) to certain (100%)
- I can identify at least three tohu (traditional signs) Māori used to predict weather
- I can evaluate forecast accuracy using a week of observation data
Hononga Marautanga · Curriculum Alignment
Curriculum alignment for this handout has not yet been verified against the live curriculum statements. A generated placeholder that stood here was removed on 2026-08-29 because it matched no real statement.
Whakataukī
"Ka kōrero te huarere, ko te tangata e whakarongo"
The weather speaks, and people listen.
Weather prediction matters. Farmers, fishers, pilots, and event organisers all make decisions based on forecasts. But forecasts are not certainties — they express probability. Understanding probability helps us make better decisions in the face of uncertainty.
Tūāhua Tūponotanga · Probability Scale
| Probability | Common meaning | NZ weather example |
|---|---|---|
| 0% | Impossible | It will snow on the Auckland waterfront in January |
| 25% | Unlikely — possible but don't plan on it | Scattered showers possible |
| 50% | Even chance — flip of a coin | Could go either way |
| 75% | Likely — expect it, prepare for it | Rain expected at some point |
| 100% | Certain — it will happen | Very rare in weather forecasting! |
1. When a forecast says "70% chance of rain" — what does that actually mean? (Hint: think about 100 similar days.)
2. The forecast says 40% chance of rain. Would you take an umbrella to school? Explain your reasoning — include the consequences of getting it wrong both ways.
Pānui Matapae Huarere · Reading a Forecast
This is a 5-day forecast for your region. Use it to answer the questions below.
1. Which two days have the highest probability of rain? Convert those percentages to fractions in simplest form.
2. You have an outdoor event planned for Tuesday. Based on the probability, should you have a backup plan? Justify your answer.
3. If you repeat the experiment of this week 10 times, on how many Wednesdays out of 10 would you expect rain? Explain.
Pēhea te Hanga Matapae · How Forecasts Are Made
Modern meteorologists combine multiple data sources to produce probability forecasts. Match each tool to its function in the space provided.
| Tool | What it measures / does |
|---|---|
| Satellites | |
| Weather balloons | |
| Weather stations | |
| Supercomputers |
Why can't weather forecasts be 100% accurate? Give two reasons.
Tohu Huarere · Traditional Weather Signs
Māori developed sophisticated observation-based systems for predicting weather over hundreds of generations. These tohu (signs) were embedded in Maramataka and encoded in community knowledge.
Indicates spring has arrived — planting time begins
Summer is here — coastal and fishing activities peak
Good weather tomorrow — pressure system moving through
Dry conditions coming — from the Pacific
Deep-sea fish near surface = weather change approaching
Seasonal shift — timing of planting and harvest decisions
1. Choose two tohu from above and explain how they might work scientifically — what natural mechanism might make them reliable predictors?
2. In what ways is Maramataka observation similar to modern meteorology? In what ways is it different?
Pukapuka Huarere · Weather Diary (1 Week)
Record forecast vs actual weather for 5 days. At the end, evaluate how accurate the forecasts were.
| Day | Forecast (% chance of rain) | Actual weather | Did it rain? (Y/N) | Was the forecast helpful? |
|---|---|---|---|---|
| Monday | ||||
| Tuesday | ||||
| Wednesday | ||||
| Thursday | ||||
| Friday |
After completing the diary: Were there any forecasts that were clearly wrong? What does this tell you about weather prediction?
Aronga Mātauranga Māori
Meteorology and Maramataka are not competing systems — they are complementary approaches to the same challenge: understanding and predicting the natural world. NIWA (National Institute of Water and Atmospheric Research) increasingly works alongside Māori knowledge holders to integrate tohu-based observation with instrumental data. Some iwi-based environmental monitoring programmes now record Maramataka observations alongside temperature, rainfall, and wind data, building datasets that span traditional and scientific time frames.
In te ao Māori, whakaaro (careful thinking) and tūhura (observation) are central values. Both science and Maramataka share these foundations — the difference is in the tools, not the attitude.
Ngā Rauemi Tautoko · Support Materials
Resources already provided:
- This handout with probability tables and weather diary grid
- MetService (metservice.com) or NIWA CliFlo — for today's regional forecast
- Calculator (permitted throughout)
- Unit vocabulary list: probability, forecast, tohu, Maramataka, uncertainty
Aronga Rerekē · Differentiated Pathways
Tīmata · Entry Level
Read the probability scale and answer questions 1 and 2. Complete the 5-day forecast questions. Start the weather diary.
Paerewa · On Level
Complete all sections. Complete the full weather diary over one week. Answer all questions including the traditional knowledge comparison.
Tūāpae · Extension
Complete all sections. After your week of observation, calculate what percentage of forecasts were accurate (rain predicted and rain occurred). Compare this to NIWA's stated forecast accuracy rates. Write a paragraph evaluating weather forecasting as a probability-based tool.
Curriculum alignment
- Reading — Making Meaning: Integrate sources of information, processes, and strategies confidently to identify, form, and express ideas.
- Writing — Creating Meaning: Integrate sources of information, processes, and strategies confidently to identify, form, and express ideas.