If it is an option, it would be wise to have both the Austin (AUS) to Newark (EWR) leg and Newark (EWR) to Tel Aviv (TLV) leg booked on the same itinerary. If nothing else, this should mean that United will make sure that you get on a subsequent flight at no extra charge if the connection doesn't work out.

Based on personal experience, I once had a United flight from Austin to Newark sit on the runway for at least a couple of hours due to "waiting for the arrival of a late inbound crew" and I missed the international connection in Newark.

It was supposed to be a comfortable layover of 3 to 4 hours or so, but it was not. It was a driven to the gate in a cart honking all the way kind of experience only to discover that the international flight still was on the runway, but it had closed and I was not allowed to board. United put me up for the night in a hotel and I departed from Newark the subsequent evening.

4.5 hours should be enough time, if everything goes as intended. However, in the last 30 days, UA 324 out of Austin had its departures delayed 12 times and arrived late 7 times. Unless I'm missing something, it also appears to be scheduled to arrive in Newark an hour or so later than you specified in your question, so double check those times.

For UA 324, at least one of those delays certainly would cause you to miss the connecting flight. Others look like you could fall into the same trap I did. On the other hand, in the last 30 days, UA 90 also had its departures delayed 28 times, which might improve your odds a bit if boarding still is allowed.

Hope this helps you calculate your odds. If you cannot book the flights together on the same itinerary, you might prefer to instead book an earlier flight out of Austin.

If it is an option, it would be wise to have both the Austin (AUS) to Newark (EWR) flight and Newark (EWR) to Tel Aviv (TLV) flight booked on the same itinerary as a single Austin to Tel Aviv journey. If nothing else, this should mean that United will make sure that you get on a subsequent flight at no extra charge if the connection doesn't work out.

Based on personal experience, I once had a United flight from Austin to Newark sit on the runway for at least a couple of hours due to "waiting for the arrival of a late inbound crew" and I missed the international connection in Newark.

It was supposed to be a comfortable layover of 3 to 4 hours or so, but it was not. It was a driven to the gate in a cart honking all the way kind of experience only to discover that the international flight still was on the runway, but it had closed and I was not allowed to board. Because it was booked as a single ticket, though, United put me up for the night in a hotel and then I departed from Newark the subsequent evening (after enjoying an unexpected day wandering around in NYC).

4.5 hours should be enough time if everything goes as intended. However, in the last 30 days, UA 324 out of Austin had its departures delayed 12 times and arrived late 7 times in Newark. Unless I'm missing something, UA 324 also appears to be scheduled to arrive in Newark an hour or so later than you specified in your question, so double check those times.

For UA 324, at least one of those delays certainly would cause you to miss the connecting flight. Others look like you could fall into the same not quite enough time trap I did. On the other hand, in the last 30 days, UA 90 also had its departures delayed 28 times, which might improve your odds a bit if boarding still is allowed.

Hope this helps you calculate your odds. If you cannot book the flights together on the same United ticket itinerary, it would be a good idea to instead book an earlier flight out of Austin.