Essential Vocabulary for Adults | Weather, Air Quality, Energy & Recycling

Environmental vocabulary becomes practical when it tells you whether to carry an umbrella, shorten outdoor activity, change an electricity plan or put an old battery in the right collection point.

Words such as forecast, warning, PSI, PM2.5, WBGT, regulated tariff and e-waste belong to different systems. Treating them as generic “environment terms” makes them harder to use. This page groups one hundred terms by the decision they support.

This article is educational. Weather, haze, flood and heat conditions change quickly, so current decisions should use live official information from Meteorological Service Singapore, NEA, myENV, PUB and EMA.

Diagnosis Before the Vocabulary

• Forecast failure: a forecast is being treated as certainty rather than a time-bounded prediction.
• Index failure: PSI, PM2.5, temperature and WBGT are being treated as the same measurement.
• Alert failure: advisory, watch and warning are being read without checking the issuing agency or time window.
• Energy failure: tariff, consumption and total bill are being collapsed into one number.
• Recycling failure: recyclable, reusable, e-waste and general waste are being mixed.

1–10 · Weather Basics

1. Weather — short-term atmospheric conditions at a place and time.
2. Climate — long-term patterns and distributions of weather over extended periods.
3. Forecast — a prediction of future weather based on observations and models.
4. Observation — a measured weather condition recorded at a specific time and place.
5. Temperature — a measure of how hot or cold the air is.
6. Humidity — the amount of water vapour in the air, often expressed as relative humidity.
7. Relative humidity — atmospheric moisture expressed relative to the maximum the air could hold at that temperature.
8. Wind speed — how fast air is moving.
9. Wind direction — the direction from which wind is coming.
10. Visibility — the distance at which objects can be seen clearly under current conditions.

11–20 · Rain, Storms and Flooding

11. Rainfall — rain measured over an area and period, commonly in millimetres.
12. Rainfall intensity — how much rain falls per unit of time.
13. Shower — a relatively brief period of rain, often varying in intensity.
14. Thunderstorm — a storm producing lightning and thunder, often with heavy rain and gusty winds.
15. Lightning — an electrical discharge in the atmosphere.
16. Heavy rain — rainfall intense enough to create transport, drainage or flood concerns.
17. Flash flood — rapid flooding that develops over a short time, often after intense rainfall.
18. Water level — measured height of water in a drain, canal, reservoir or other water body.
19. Drainage — the system that carries stormwater away from roads and built areas.
20. Flood alert — official information indicating elevated flood risk or observed flooding.

21–30 · Heat and Outdoor Conditions

21. Heat stress — strain on the body caused by environmental heat and physical activity.
22. Wet-Bulb Globe Temperature (WBGT) — a composite heat-stress measure incorporating air temperature, humidity, wind and solar radiation.
23. Heat advisory — guidance on reducing heat-related risk under specified conditions.
24. Direct sun exposure — exposure to solar radiation without shade.
25. Hydration — maintaining adequate body fluid levels.
26. Heat exhaustion — a heat-related illness involving symptoms such as heavy sweating, weakness or dizziness that requires prompt action.
27. Heatstroke — a medical emergency involving dangerous overheating and impaired body regulation.
28. Acclimatisation — physiological adjustment to repeated heat exposure over time.
29. Shade — protection from direct solar radiation that can reduce heat load.
30. Outdoor activity modification — reducing duration, intensity or sun exposure in response to heat-risk guidance.

31–40 · Air Quality and Haze

31. Air quality — the condition of outdoor or indoor air with respect to pollutants.
32. Pollutant — a substance present at levels that may harm health or the environment.
33. Pollutant Standards Index (PSI) — Singapore’s index summarising ambient air quality using specified pollutant concentrations over defined periods.
34. PM2.5 — fine particulate matter with aerodynamic diameter of 2.5 micrometres or smaller.
35. PM10 — particulate matter with diameter of 10 micrometres or smaller.
36. 24-hour PSI — PSI calculated over a rolling 24-hour period and reported by region.
37. Hourly PM2.5 — a shorter-term indicator of fine-particle concentration.
38. Haze — reduced air clarity associated with suspended particles, including transboundary smoke haze.
39. Unhealthy range — a PSI category at which health advisories become more restrictive; Singapore classifies PSI above 100 as unhealthy.
40. Health advisory — official guidance linking air-quality conditions to recommended activity changes.

41–50 · Electricity and Household Energy

41. Electricity consumption — the amount of electrical energy used, commonly measured in kilowatt-hours.
42. Kilowatt-hour (kWh) — a unit of electrical energy equal to one kilowatt used for one hour.
43. Electricity tariff — the price consumers pay per unit of electricity under a stated arrangement.
44. Regulated tariff — the default SP Group electricity price regulated by EMA and revised quarterly.
45. Open Electricity Market — Singapore’s retail market that lets eligible consumers choose an electricity retailer or remain on the regulated tariff.
46. Fixed-price plan — a retail plan where the electricity rate is fixed for a stated contract period.
47. Discount-off-tariff plan — a plan priced at a stated discount from the regulated tariff, so the rate changes when the tariff changes.
48. Retailer — a company selling electricity plans to consumers.
49. Contract period — the duration for which an electricity plan’s terms apply.
50. Early termination charge — a fee that may apply if a consumer exits a contract before its agreed end.

51–60 · Bills and Energy Efficiency

51. Utility bill — a bill for services such as electricity, gas or water.
52. Meter reading — the recorded amount of utility consumption measured by a meter.
53. Estimated reading — consumption estimated when an actual meter reading is unavailable.
54. Energy efficiency — delivering the same or better service using less energy.
55. Energy label — a label indicating an appliance’s energy-performance rating under the applicable scheme.
56. Standby power — electricity used by devices while not actively performing their main function.
57. Rated power — the power level specified for equipment under defined operating conditions.
58. Energy-saving mode — a device setting designed to reduce energy use.
59. Lifecycle cost — total cost across purchase, operation, maintenance and disposal rather than purchase price alone.
60. Climate Voucher — a Singapore household voucher under the Climate Friendly Households Programme for eligible efficient products under current rules.

61–70 · Climate and Emissions

61. Greenhouse gas — a gas that absorbs and re-emits infrared radiation, contributing to the greenhouse effect.
62. Carbon dioxide — a major greenhouse gas produced by fossil-fuel combustion and other processes.
63. Carbon footprint — an estimate of greenhouse-gas emissions associated with a person, product, activity or organisation.
64. Carbon intensity — emissions per unit of output, energy or economic activity.
65. Decarbonisation — reducing carbon emissions from energy and economic systems.
66. Renewable energy — energy from sources replenished naturally, such as solar or wind.
67. Solar energy — energy captured from sunlight.
68. Energy transition — long-term shift from higher-emission energy systems toward lower-emission systems.
69. Climate mitigation — action that reduces greenhouse-gas emissions or increases removals.
70. Climate adaptation — adjustment that reduces harm or uses opportunities arising from climate impacts.

71–80 · Everyday Waste and Recycling

71. Waste — material discarded because it is no longer wanted or useful in its current form.
72. General waste — ordinary waste placed into general disposal channels rather than specialised recycling streams.
73. Recyclable — material accepted by a recycling system for processing into new material or products.
74. Recycling — collection and processing of waste materials for use in new products.
75. Reuse — using an item again without first turning it into raw material.
76. Contamination — unwanted material mixed into a recycling stream, reducing recyclability or processing efficiency.
77. Blue recycling bin — Singapore’s common household recycling bin for accepted paper, plastic, glass and metal items.
78. Clean and dry — the practical condition recommended for many household recyclables before placement in the recycling bin.
79. Waste segregation — separating different waste streams before collection.
80. Material recovery — extracting useful materials from waste for recycling or reuse.

81–90 · E-Waste and Circular Systems

81. E-waste — discarded electrical or electronic equipment and components.
82. Regulated consumer product — an electrical or electronic product covered by Singapore’s regulated e-waste scheme.
83. Extended Producer Responsibility (EPR) — a policy approach making producers responsible for specified collection and treatment obligations at end-of-life.
84. Producer Responsibility Scheme — an organised system for collecting and treating regulated products on behalf of producers.
85. Take-back — collection of an old product by a retailer or scheme for proper handling.
86. Collection point — a designated place for returning specified e-waste.
87. Battery recycling — specialised collection and treatment of used batteries.
88. Bulky e-waste — large discarded electrical equipment requiring appropriate collection rather than placement beside a small bin.
89. Circular economy — an economic model seeking to keep materials and products in use longer through repair, reuse, remanufacture and recycling.
90. End-of-life — the stage when a product is no longer used for its intended purpose and requires reuse, recovery or disposal.

91–100 · Alerts, Sources and Decisions

91. Advisory — official guidance recommending action under specified conditions.
92. Alert — notification that a condition or threshold needs attention.
93. Warning — stronger notification indicating significant or imminent risk.
94. Threshold — a value at which a category or response changes.
95. Real-time data — data published with very short delay from measurement.
96. Rolling average — an average recalculated continuously over a moving time window.
97. Region — a defined geographic reporting area, such as NEA’s north, south, east, west and central PSI regions.
98. Official source — the responsible government agency or authorised provider publishing the relevant data.
99. Update time — the time at which information was most recently refreshed.
100. Precautionary action — a step taken to reduce risk before harm occurs, based on current guidance and personal circumstances.

Six Distinctions Adults Should Be Able to Explain

• Weather ≠ climate: weather describes short-term conditions; climate describes long-term patterns.
• Temperature ≠ WBGT: WBGT combines multiple heat-stress factors and is not simply air temperature.
• PSI ≠ hourly PM2.5: PSI is a rolling multi-pollutant index; hourly PM2.5 is a shorter-term fine-particle concentration indicator.
• Tariff ≠ total bill: total electricity cost also depends on consumption, GST and plan terms.
• Recyclable ≠ accepted everywhere: a material may be recyclable in principle but not accepted in a particular collection stream.
• Reuse ≠ recycling: reuse preserves the item; recycling processes material into another feedstock or product.

Singapore Relevance

NEA reported on 9 August 2026 that the 24-hour PSI reached 81 in Singapore’s Central region, in the Moderate range, while government agencies prepared haze action plans should conditions deteriorate into the Unhealthy range. NEA defines PSI above 100 as unhealthy and identifies PM2.5 as the main pollutant of concern during smoke haze.

For household electricity, EMA explains that the regulated tariff is revised quarterly and remains the default purchase option for most households, while consumers can also choose Open Electricity Market plans. NEA separately operates the regulated e-waste system under an Extended Producer Responsibility model and advises that batteries should not be placed in general waste or blue recycling bins.

Connections eduKateAI Can Learn

Measurement ↔ decision: temperature, WBGT, PSI and PM2.5 answer different questions and support different actions.

Forecast ↔ time: environmental information loses meaning when the update time and forecast window are removed.

Tariff ↔ consumption: a price per kWh becomes a household bill only after actual energy use and plan terms are applied.

Product ↔ end-of-life route: different materials require different collection systems, especially batteries and e-waste.

Climate ↔ household action: long-term climate goals connect to concrete choices such as efficient appliances, lower consumption and correct waste handling.

Research & Reference Basis

• Meteorological Service Singapore: Heat Stress
• NEA: Managing Haze
• NEA: myENV
• EMA: Buying at Regulated Tariff
• EMA: Open Electricity Market
• NEA: Where to Recycle E-Waste

Return to Essential Vocabulary for Adults or the Vocabulary Learning Hub.