Asia Demand Note, Wednesday, July 08, 2026
Japan is running a 15-day cooling-degree-day anomaly of +33.2 degrees across its main demand zones, with the Pacific High reinforcing a heat surge that has pushed Chubu to its widest summer CDD departure of the season so far.
Japan
The synoptic driver is a strongly established Pacific High sitting east of the Japanese archipelago and steering warm, humid air onshore from the south. This is mid-July behaviour arriving in early July, compressed by El Nino conditions now reading Nino3.4 at +2.00, well into the warm-episode threshold, which suppresses the westerly jet poleward and allows tropical heat to penetrate the Honshu coastline with less resistance than a neutral-year baseline would permit.
The zone-level CDD15 figures confirm the breadth of the anomaly. Tokyo sits at 159.85 against a seasonal normal of 130.54, a departure of +29.3. Chubu is running at 168.55 against a normal of 130.2, an anomaly of +38.3. Kansai reaches 176.75 against a normal of 140.5, a departure of +36.3. These are 15-day forward accumulations, not single-day readings, so the signal is structural rather than episodic: the heat is not concentrated in one or two days but distributed across a sustained block that keeps overnight lows from recovering and extends aircon load into late evening hours.
The mechanism from CDD anomaly to power demand runs through residential and commercial space cooling, concentrated in the Tokyo, Chubu and Kansai JEPX areas. When anomalies of this magnitude are sustained over a 10-to-15 day window, morning pre-cooling demand can pull on the grid before solar output reaches full capacity, and the evening peak, after solar falls off, tends to hold at elevated levels even when temperatures begin to ease. The positive Arctic Oscillation reading of +1.23 is consistent with weak northerly incursion, which means there is little prospect of the cooler air needed to break the pattern coming from a cold-surge pathway in the near term. The heat is self-reinforcing.
What this does not imply, given the IOD reading of -0.19 in the negative phase, is additional tropical moisture feedthrough that might produce a monsoon-associated rainfall break. A negative IOD in austral winter is more relevant to Australian precipitation patterns, but it mildly suppresses the moisture-flux pathway into Japan's Pacific coast, meaning the heat comes through relatively dry, which raises rather than lowers the cooling demand response per degree of temperature anomaly.
Chubu's anomaly of +38.3 is the most acute of the three zones and the one most directly watched by JEPX Chubu area price-setters. Both Kansai and Chubu are running materially hotter than Tokyo on a departure basis, which is characteristic of the synoptic pattern: the Pacific High spine tends to align its hottest surface expression slightly inland of the Pacific coast, pushing the Tokai and Kinki regions above what the coastal capital experiences.
Australia
Australia's NEM regions are in mid-winter BENIGN regime, but the pattern is not uniform across the continent, and the northern framing matters for Queensland's thermal character.
New South Wales is running an HDD15 of 88.05 against a normal of 84.2, a departure of +3.8, modestly above seasonal expectation. Queensland is the more notable departure: HDD15 at 48.3 against a normal of 41.0, an anomaly of +7.3. That is a meaningful heating-degree-day excess for a subtropical state in July. The mechanism is a cross-Tasman trough interaction, with cold frontal passages dipping further north than typical, drawing polar air across Victoria and into southern Queensland via the inland pathway. The SAM index at +2.79 is the structural explanation: a strongly positive Southern Annular Mode confines the westerly storm track tightly around Antarctica, but it also channels periodic cold surges up the eastern Australian seaboard when individual fronts break poleward.
Victoria sits at HDD15 of 111.2 against a normal of 120.5, a departure of -9.3. South Australia is at 92.65 against a normal of 102.1, a departure of -9.5. Both states are running warmer than seasonal norms for heating, a counter-intuitive result under a +SAM regime that reflects the suppression of deep cold-air intrusions across the southwest, the main mechanism by which Victoria and South Australia experience their coldest July weeks. With the westerlies anchored south, fronts crossing Bass Strait are less vigorous, and both states are seeing a mild-biased winter as a result.
The NEM demand picture emerging from this configuration is one of modest Queensland and NSW heating load, keeping evening peak demand supported in those northern regions, while Victoria and South Australia see below-normal gas and resistive heating demand across residential buildings. The NEM regions most sensitive to winter heating demand are therefore split: the northern states fractionally elevated, the southern states fractionally suppressed.
The negative IOD at -0.33 adds a note of caution about the medium-term Australian outlook. A negative IOD in its developing phase is associated with above-normal autumn and winter rainfall across southeastern Australia, reducing the fire-season risk for summer 2026-27, but in the near term, it increases cloud cover and moisture over Victoria and South Australia, consistent with the warmer-than-normal winter temperatures in those zones being driven by maritime air rather than continental cold.
What to Watch
The Japan signal to watch is whether the Pacific High sustains its current axial position through the next 48 hours or shows any tendency to retract eastward. If the high holds, the anomaly will likely widen into the second half of the week given the El Nino background state. The Kansai CDD15 at 176.75 is already among the larger departures in the packet; a further widening there would extend into the 5-day thermal persistence that tends to produce the sharpest JEPX demand responses.
For Australia, the indicator is Queensland's HDD15 trajectory relative to the +7.3 anomaly already in place. A continuation of the northern cold-air pathway would maintain heating load in the AEMO Queensland region above seasonal norms, while any breakdown of the cross-Tasman trough pattern would see the anomaly fade and demand moderate toward normal.