Airtankers do not put fires out, people on the ground put fires out. Air tankers can only slow fires' spread - you'll notice that what they drop is called retardant, not extinguisher. Using air tankers without ground support is a delaying tactic only. It's not too hot to try to manage the fires from the ground - people are out there on the ground.
The C-130s that you are seeing are military - there are no civilian C-130 air tankers. The military ships are fitted with removable tank systems - MAFFS - and there are a limited number of those. MAFFS are less effective than dedicated gated retardant ships, but they're better than nothing.
This year there are only 7 large air tankers on contract to the US gov't. There were 9 but two crashed. MAFFS, Canadian Convairs on loan, single engine air tankers, and helicopters are trying to take up the slack, but decreased funding from Congress and inertia on the part of the fed agencies has led to the current woeful state of the large air tanker fleet in the US.
The DC10 tanker has been activated on a call-when-needed basis by the feds but the drop height it requires and it's lack of maneuverability make using it problematic (and occasionally useless) in high winds and tight terrain.
Ya, it's a mess and getting worse.
No new parts, support for C-130 wildfire system
CHEYENNE, Wyo. – The demise of the only company that manufactured a device specially designed to spray fire retardant from the back of U.S. military C-130 cargo planes has some experts worried about the future viability of a program that has helped fight wildfires for 40 years.
The Modular Airborne Firefighting System is a bus-sized device that can be shoved into the belly of a cargo plane and then used to spray retardant, or slurry, at 3,000 gallons in less than 5 seconds. The $4.9 million device's only manufacturer, Sacramento, Calif.-based Aero Union, went out of business in August, and no other company has replaced it. Critical spare parts also are no longer being made.