Goof: When Hawkins puts on the yellow chemical suit, he wraps tape around his wrists and ankles. However, every time we see him in the suit after there is no tape anywhere.
The anchorman said: "So far, we knew...the following cities...Seattle, Atlanta, Dallas..." The simplified Chinese shown on TV is "blood flute" and "he".
Goof: The car that Jake is driving, when he finds the plane on the road, has no number plate.
Goof: After Johnston punches Gray and talks to him, he opens to the door to allow Gray out. When Gray is just about to walk out, you can see a shadow that isn't from Johnston. It looks like a shadow from the camera.
The episode title "Four Horsemen" refers to how the townspeople organize for 4 different teams to explore in all four directions outside of Jericho.
Judging by the map in the Sheriff's office, Jericho is approximately where the small town of Lincoln, Kansas should be.
When the Asian satellite broadcast is on for a few seconds, showing the map, the only city visible other than the ones mentioned or shown in the "thumbtack map" scene appears to be Dallas/Fort Worth. Philadelphia, Atlanta, Chicago, San Diego and Denver are shown highlighted. Later someone mentions Seattle or maybe Portland, Oregon, but this part of the map is obscured by a Tiffany lamp shade.
The morse code that plays over the opening is:
Gail: Where's Emily?
Jake: She's not going.
Gail: Good. You're not going alone are you?
Jake: Yeah, don't give me that look.
Gail: What look?
Jake: You know what look, that look.
Gail: Hey, I do this 72 hundred times, I've watched you drive away not knowing if you were coming home, I've earned a look.
Jake: I'm coming back.
Gray: The four horsemen of the apocalypse.
Jake: Let's hope not.
Eric: Jake, what are you doing back?
Cop: You should be in Wichita by now.
Jake: Smokey hill bridge is blocked. (He unzips the bag he just set down on the table)
Eric: What is that?
Jake: It's a flight data recorder. (There is a red box inside the bag clearly labeled Flight Data Recorder)
Cop: I thought they were supposed to be black?
Gail: You know I keep thinking about when we were kids and how they used to make us practice hiding under our desks in case of an atomic bomb.
Johnston: Yeah and duck for cover.
Gail: That's the first thing I thought of when I saw that mushroom cloud. Did they have enough time to hide under their desks? It's pretty stupid huh.
Stanley: Are you okay?
Mimi: Huh, if you call radiation poisoning 'okay.'
Stanley: Were you out in the rain, too?
Mimi: Heavens no! I touched a building when we came out of the shelter.
Mimi: Look, you can stop pretending.
Stanley: What do you mean?
Mimi: I audited your farm. Why do you care?
Stanley: Maybe I'm a nicer person than you.
Mimi: Right. Were you in the rain?
Stanley: Yeah, for about twenty minutes.
Mimi: Well, you look pretty good.
Stanley: Thanks. You know, I try to work out.
Stanley: Look, um, you know I think I got the worst of it, so as long as I'm okay, you should be fine.
Mimi: You're really sweet. And you still owe the IRS $180,000.
Stanley: Yeah, I know.
(Mimi rests her hand on a column, and when she lifts it, her hand is covered in black)
Mimi: What's this black stuff?
Mary: That used to be Denver.
Eric: I don't know if I told you this, but my father is impervious to mere germs.
April: Oh really?
Mayor Green: Yeah, I believe that was the quote.
Gail: First inauguration, I have it all on video.
Mayor Green: It was a joke, I was trying to... April, don't ever make a mistake, this family will never let you forget it!
Bonnie: Stanley! (Runs to Stanley)
Stanley: Thank God!
Jake: No, hey, hey, no! (Pulls Bonnie back) Stanley don't touch her. The rain may be radioactive.
Mayor Green: In my office. Now. (Punches Gray Anderson) Right now these people need our leadership. I will not have you tearing this town apart. And when all this is over, if you and I are still alive, you investigate your ass off. In the meantime, if I hear anymore talk like that out of you, you and I are gonna have a problem. Do we understand each other?
Jake: Going out is more important then ever, alright? If this country is at war we need to know it!
Mayor Green: I can't just sit around here all day. We've got to find the sheriff and his men; we've got to get the power back on.
Gail: Okay, now you're going to stay here as long as it takes. Now, don't make me take your pants with me.
Mayor Green: I can run this town without my pants.
Gail: It wouldn't be the first time.
Stanley: Yeah..I'm really sick of getting poked with needles every ten minutes. They'll be really sorry when my spider powers kick in. (makes a goofy face)
Jake: Well, you're still an idiot, so that's a good sign.
Stanley: (laughs) Yeah.
Australia: October 5 2006, Network Ten
Denmark: October 17 2007, SBS Net
Estonia: May 23 2007
Finland: September 5 2007
Germany: June 11 2007, Pro7
Hungary: December 24 2006
Mexico, October 9 2007
Netherlands: May 26 2008
United Kingdom: January 26 2007, Hallmark
Slovenia: September 29 2008, Kanal A
Stanley: They'll be really sorry when my spider powers kick in.
Stanley was in the radioactive rain for 20 minutes and is referring to the Spider-Man Marvel Comics. Peter Parker was bitten by a radioactive spider and that gave him superhero "spider powers".
Four Horsemen (of the apocalypse) are mentioned in the Bible in the Sixth Chapter of the Book of Revelations.
The four horsemen are named Pestilence, War, Famine, and Death.