Lumen Sites for mine & construction sites

Bowen Basin weather for site work

The Bowen Basin in central Queensland is Australia’s main source of coking coal, with mines around Moranbah, Dysart, Middlemount, Emerald, Blackwater and Moura. It rarely gets as hot as the Pilbara or the Goldfields, but its humidity makes heat stress far more common, and most of the year’s rain falls in a few summer months.

The year at a glance

Summers are hot and humid, with average highs of about 34° from December to February, and they bring most of the rain. Winters are dry and mild, with July nights averaging 7–10°. Annual rain is about 540–680 mm, and 54–69% of it falls from December to March.

Averages for 1995–2024 from SILO (Queensland Government, CC BY 4.0), interpolated from Bureau of Meteorology observations. Heat-stress days: estimated WBGT reaching 28°, the caution level Lumen Sites starts with. Select a town for its month-by-month figures.
Town	January high	July low	Rain a year (mm)	Wettest month	Days reaching 40°	Heat-stress days
Moranbah	34°	9°	588	Feb 105 mm	3	199
Emerald	35°	9°	563	Jan 90 mm	5	185
Dysart	34°	9°	614	Jan 112 mm	1	189
Clermont	34°	7°	588	Jan 108 mm	5	186
Middlemount	34°	9°	604	Jan 108 mm	1	190
Blackwater	34°	9°	552	Dec 86 mm	3	180
Moura	35°	7°	609	Dec 98 mm	3	181
Tieri	34°	9°	567	Jan 103 mm	2	180
Capella	34°	8°	541	Jan 97 mm	3	186
Glenden	33°	9°	657	Feb 141 mm	under 1	186
Collinsville	34°	10°	682	Feb 148 mm	1	222

Heat stress: humidity does the damage

Heat-stress days by month

Average heat-stress days a month, 1995–2024: days when the estimated wet bulb globe temperature (WBGT) at the day’s peak reaches 28°, the caution level Lumen Sites starts with. From SILO (Queensland Government, CC BY 4.0), interpolated from Bureau of Meteorology observations.
Town	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Moranbah	31	28	29	18	4	1	<1	2	9	21	27	30
Emerald	30	27	29	15	3	<1	<1	1	7	18	25	29
Dysart	30	28	29	17	3	<1	<1	1	6	19	25	30
Clermont	30	27	29	16	3	<1	<1	1	7	19	25	29
Middlemount	31	28	29	18	4	1	<1	1	6	18	25	30
Blackwater	30	27	28	14	3	<1	<1	1	6	17	24	29
Moura	31	27	29	16	3	<1	<1	1	6	17	23	29
Tieri	30	27	28	15	3	<1	<1	1	6	17	24	29
Capella	30	27	29	16	3	<1	<1	1	6	19	25	29
Glenden	30	28	29	15	3	<1	<1	1	6	18	26	30
Collinsville	31	28	31	24	7	2	1	3	12	24	28	31

Most Bowen Basin towns reach 40° only a few days a year, but humid summer days push the estimated wet bulb globe temperature (WBGT) up. Moranbah averages 199 heat-stress days a year, 78 of them at the stop level, against 56 and 9 in Kalgoorlie, which reaches 40° more often but is far drier.

The heat-stress season is long, too: Moranbah averages at least 21 heat-stress days in every month from October to March. These figures use the Bureau of Meteorology’s simplified formula, which assumes moderate sun and light wind, so read them as how often heat needs managing rather than as days work must stop. The WBGT calculator shows how quickly humidity lifts the estimate.

The wet season and floods

December to February are the wettest months, with around 75–150 mm a month in most towns, mostly from thunderstorms and monsoon or tropical lows. The black clay soils common across the region turn roads slippery and boggy after rain.

Big wet seasons can be severe. In 2010–11, flooding across central Queensland filled pits and cut the rail lines to the coal ports, and dewatering took months at some mines. Cyclones that cross the coast between Mackay and Bowen can also bring damaging winds and heavy rain inland, as Cyclone Debbie did in March 2017. See rain, the wet season and haul roads and cyclone season for remote sites.

Storms and lightning

Thunderstorms are most common from about October to March. They bring lightning, damaging gusts, hail and heavy downpours, often building in the afternoon and evening, so lightning stand-downs are part of every summer. Lightning stand-down alerts covers setting stop and warning distances for a site.

The dry season

May to September is dry and mild, and July to September are the driest months in most towns. It is the most dependable window for major shutdowns, earthworks and heavy outdoor work. Clear, calm winter nights also set up temperature inversions, so morning blasts need the same care as anywhere inland.

Planning a year on site

Put major shutdowns and earthworks into May to September.
Run heat stress plans from October to March, not just in midsummer.
Before December, check drainage, pumps and pit sumps, and plan for roads and rail being cut.
Expect storms most summer afternoons, and have lightning detection rather than relying on hearing thunder.