What time is the border shortest?
By Alan Scott · Who makes this · Tijuana, Baja California ·
It's the single most searched question about the border. And we're going to give you the answer nobody gives you:
We don't know yet, from data. And anyone who gives you an exact hour doesn't know either.
Hold the frustration for two minutes, because the explanation will serve you for the rest of your life as a user of these apps.
The public historical data is full-day averages
The historical border wait data is published as one average per day. A Sunday shows up as "102 minutes" and that's it.
That number could be any of these:
- An even Sunday, 100 minutes all day long
- A Sunday of 40 minutes in the morning and 180 in the afternoon
- A Sunday with three terrible hours and the rest empty
All three average the same. And they're three completely different days for you.
So when someone derives a recommended hour from public historical data, they are inventing the missing part. The data they used has no hours inside it.
And the "current" number is published once an hour
Here's the other half, and we measured this directly at the official source:
CBP publishes border wait times once an hour, on the hour.
We counted it across the 85 crossings CBP reports: 72 of 77 lanes updated exactly on the hour.
That means the freshest number that exists anywhere about the border can be up to 59 minutes old. It doesn't matter which app you open: if it shows you a number, that number came from the same place and is the same age.
Nobody has live data. It doesn't exist.
When an app shows you a wait time without telling you when it was measured, it isn't necessarily lying on purpose — but it is letting you believe the number is from this second, and it isn't.
What we can tell you today, with data
Not knowing the hour doesn't mean we know nothing. This is measured:
| Question | Measured answer |
|---|---|
| What's the best day of the week? | Friday, 71 min vs. 102 on Sunday |
| What's the best month? | January, 69 min vs. 100 in December |
| What are the worst days of the year? | December 15–23, up to 56 min above normal |
| And the emptiest? | December 24, nearly an hour less |
| When does it get ugly without warning? | The Tuesday after a U.S. holiday: 7 out of 7 times |
| Is it worth crossing on foot? | On foot takes about a fifth of the time. With Ready Lane, 3 minutes |
That's enough to plan your week. What's missing is the hour, and for that you need data nobody is saving.
What we're doing about it
Saving CBP's number every 5 minutes, every day, from day one.
Not to have the fastest data — we just showed you that doesn't exist — but to accumulate what doesn't exist anywhere: the hour-by-hour history.
Once we have a few months of it, this page will be able to answer itself, with our own measured numbers. And when that happens, you'll see it here, including how often we got it right.
In the meantime we'd rather tell you "we don't know" than invent an hour for you. That's what will make us useful when we do know.
What this article does NOT say
It doesn't say other apps are lying. It says the source we all use publishes once an hour, and that the public historical data is daily averages. With those two limits, nobody can give a supported exact hour. Including us.
And it doesn't say the hour doesn't matter. It matters enormously — it's probably the single most valuable piece of data there is. That's exactly why we're not going to fake it.
What is measured:
- Friday is the best day to cross at San Ysidro
- July is the worst month and January is the best
- The worst days of the year are December 15–23
- If you cross on foot, forget what you know about the car line
Sources
CBP publication cadence: measured directly at https://bwt.cbp.gov/api/waittimes, counting the update_time field across the 85 crossings it reports. 72 of 77 lanes with data updated on the hour. Historical granularity: the SANDAG dataset publishes one average per day per crossing and lane type. It contains no hours. Historical period: January 29, 2023 to August 8, 2026 · 1,266 days. Retrieved: August 11, 2026.
We are not affiliated with CBP or SANDAG.
CHART · build spec
Same illustrative chart as the Spanish version — see 6_CONTENIDO/articulos/08_a_que_hora_esta_mas_corta.md.
🔴 The mandatory label stays, translated: "Illustrative example. Not real data — which is exactly why this article exists." Without that label the chart contradicts the article.
And the caption below: "All three days average 102 minutes. They are three completely different days."