WattMarkets
— PT
PJMWARNINGPeak probability 100% today · window 3:00 PM ET–6:00 PM ET

Day-ahead vs. real-time

Every morning the day-ahead market prices tomorrow, hour by hour. This page grades that bet against what the grid actually paid.

Two prices for every hour

Jul 15 · PT · 3-hub average- - day-ahead — real-time
$28$38$49$59$6912 AM6 AM12 PM6 PM11 PM
Spread by hour (RT − DA)12 AM: −$1.861 AM: −$2.782 AM: −$2.313 AM: −$0.364 AM: −$0.085 AM: +$5.286 AM: +$0.377 AM: −$0.248 AM: −$0.979 AM: +$1.7010 AM: +$5.5311 AM: +$5.4212 PM: +$6.001 PM: +$3.892 PM: −$0.333 PM: +$2.024 PM: −$1.775 PM: −$7.736 PM: −$16.757 PM: −$7.618 PM: −$4.279 PM: −$3.8610 PM: +$0.35

Where the misses landed

by hub and hour · click a hub to re-scope the chart above
settled under day-aheadsettled overnot yet gradeddeeper = bigger miss · exact numbers on hover

Hub rows rank by today's average miss. zone mean of the load-zone settlement point prices.

Today so far
$42.29
real-time average vs $43.18 day-ahead
Settled under day-ahead
59%
of 695 hours since 2026-06-15
Biggest miss of the window
+$64.00
Jul 13 8:00 AM PT: priced $35.69, settled $99.69
Tomorrow's prices
$28.03–$49.11
tomorrow's day-ahead range, cheapest to priciest hour

The premium by hour

average spread by hour
+$3−$312AM: −$1.82 over 29 hours1AM: −$2.76 over 29 hours2AM: −$3.08 over 29 hours3AM: −$3.13 over 29 hours4AM: −$3.24 over 29 hours5AM: −$3.15 over 29 hours6AM: +$0.95 over 29 hours7AM: +$1.80 over 29 hours8AM: +$2.57 over 29 hours9AM: +$2.11 over 29 hours10AM: +$2.26 over 29 hours11AM: +$2.20 over 29 hours12PM: +$1.88 over 29 hours1PM: +$2.42 over 29 hours2PM: +$2.63 over 29 hours3PM: +$2.05 over 29 hours4PM: +$0.43 over 29 hours5PM: +$0.52 over 29 hours6PM: −$3.23 over 29 hours7PM: −$1.50 over 29 hours8PM: −$2.12 over 29 hours9PM: −$2.19 over 29 hours10PM: −$1.87 over 28 hours11PM: −$2.01 over 29 hours12AM6AM12PM6PM

Average of 695 paired hours since 2026-06-15. Fills in as the record grows.

The evening ramp carries the day's scarcity, so those are the hours day-ahead prices hardest. When this chart bulges violet after sunset, that is why.

Tomorrow is already priced

the day-ahead bet
$29$4812 AM12 PM11 PM$49.11

Jul 16, as the day-ahead market cleared it. Real time starts grading at midnight.

Today by hub

day-ahead vs real-time averages
HubDay-ahead avgReal-time avgSpread
Northern California$43.82$44.88+$1.24
Southern California$44.39$41.65−$2.54
Central California$41.99$40.34−$1.36

Real-time averages cover graded hours only. Full interval detail is on the prices page.

What is the day-ahead market?

CAISO clears a day-ahead market every morning: results post by early afternoon Pacific, locking an hourly price for every hour of tomorrow. Most CAISO load settles against those prices, and the real-time market trues up the difference every five minutes.

What is DART?

Trader shorthand for the day-ahead to real-time spread. On this page the spread is real time minus day-ahead, so a positive number means the hour settled above its day-ahead price and a negative number means day-ahead carried a premium.

Why do the two prices differ?

The day-ahead price embeds a forecast of weather, demand, and which plants will run. Real time is the grid as found. California adds the evening ramp: when the sun sets and demand holds, real time can spike into a ramp that day-ahead only guessed at.

Where does this data come from?

CAISO's public OASIS feeds: day-ahead hourly and real-time five-minute prices for the three trading hubs shown here, the same feeds behind the prices page. CAISO runs on Pacific time and honors 23- or 25-hour days at the daylight-saving switch.

Prices right now →The live dashboard →What is the day-ahead market →