Nearby McClellan-Palomar Airport (IATA: CLD) (ICAO: KCRQ) in Carlsbad has a few commuter flights to/from Los Angeles International Airport on SkyWest Airlines under the United Express banner. Vision Airlines also has service to North Las Vegas.
Most travelers to/from Oceanside utilize San Diego International Airport (IATA: SAN) . Take San Diego Transit's Route 992 bus from the airport to the Santa Fe Depot and connect to the COASTER or the Amtrak Pacific Surfliner.
The next closest airport is John Wayne Airport (IATA: SNA)  in the city of Santa Ana in the Los Angeles metro area. From Santa Ana, Tustin, or Irvine, take the Pacific Surfliner or the Metrolink Orange County Line.
For private pilots, Oceanside Airport (ICAO: KOKB) is located just north of town on Highway 76.
Oceanside is located at the intersections of Interstate 5 and California State Highways 76 and 78.
Oceanside is well-connected by train. Amtrak's Pacific Surfliner  travels south to San Diego and north to Los Angeles, Santa Barbara, and San Luis Obisbo, with several trains stopping in Oceanside each day.
Oceanside is also the northern terminus of the COASTER  regional rail line to San Diego, and the southern terminus of Metrolink's  Orange County Line which heads north through Orange County to Los Angeles. A new light rail line, the SPRINTER , links Oceanside with Escondido to the east.
Thursday Night visit the Oceanside Sunset Market  for live music, interesting fast food, fresh farm produce, and exciting fresh art. It is located on Pier View Ave, just west of Coast Highway. Thursday Morning Farmer's Market is held also on Pier View, but East of Coast Highway. Lots of good, fresh organic fruits and vegetables from local farmers at reasonable prices. Fish from the Oceanside Pier. No license is required, and the bait-house on the pier can supply everything you need. You can also surfcast, fish from the rock jetty, or join a fishing party boat out of the Oceanside Harbor. Nature attractions in Oceanside Area:
Right around the Oceanside Harbor are a lot of “nature attractions.:” We have a wide variety of seabirds on the ocean, on the beach, and in the inlet to the San Luis Rey river. We love to watch the pelicans dive for their fish. There are also a pod of dolphins who regularly patrol up and down the coast. In the harbor area, there are harbor seals and noisy sea lions usually barking over near the bait dock, just North of the boat launch ramp. Grunion Runs.
Right on the beach little fish called grunion come to lay their eggs at night. They do it for 3 sequential nights every 2 or 3 weeks from March to early Fall. The three nights are determined by the moon and tides, and the dates and times of the runs are printed in most tide guides. The first night they start around 11:30, the next night an hour later and the third night another hour later. To see them you will need to bring a flashlight, and should go north of the jetty, because the street lights and the North Coast Village lights make them shy. There is also a program at the Birch Aquarium in La Jolla. Lagoon Nature Centers & Trails:
Buena Vista Lagoon:
On Coast Highway near the Oceanside-Carlsbad border is a free Nature Center and self-guided nature trail at the Buena Vista Lagoon Audobon Society. See this web site:[ http://www.bvaudubon.org/] I like it, and our grandchildren always love a short visit there. There are things of interest for all ages from toddlers to teens. It is close, and a visit of 30 minutes would be enough to visit the center and take the short nature trail. Agua Hedionda Lagoon:
A Little further South on Interstate 5 is the Agua Hedionda Lagoon, which has a brand new, beautiful nature center situated high above the lagoon at the East end of the lagoon with a fabulous view. Take the Cannon Road exit East (same exit as Legoland) but go straight on Cannon Road a few miles to top of the hill the visitors center is a building on the left side of the road near the power lines. Here’s a link to their web site:http://www.aguahedionda.org/ There are also three short trail to explore in different areas of the lagoon.
A little further South is the Batiquitos Lagoon. Exit at Poinsettia Dr and turn East. Take the first right turn south and turn into the neighborhood at the bottom of the hill, closest to the lagoon. There is a wonderful, wide trail that goes along the edge of the lagoon near some very beautiful homes. About one block after the start of the trail is a visitor center, which has a lot of interesting exhibits -- especially for children. Here is a link to their web site: http://www.batiquitosfoundation.org/newsite/index.php
A couple of exits further South is Leucadia Blvd --Go west and then take the first Left to the monarch butterfly program building and facility. Here is a link to their web site: http://www.monarchprogram.org/facility.htm They raise butterflies, and the milkweed they feed on. They also raise other types of insects. There is a small fee (donation) for entry, but very educational.
San Diego Botanical Garden:
One more exit South is Encinitas Blvd. Exit and turn East, to the San Diego Botanical Garden. There is a fee to enter, but it is a great place to spend 3 or 4 hours, and take a picnic. Everything is beautifully labeled. There are several EXCELLENT exhibits and play areas for children, including a dinosaur area, and an amazing treehouse.. Here is a link to their web site: http://www.sdbgarden.org/
San Elijo Lagoon:
A few exits further south is Manchester Ave -- go west to San Elijo Lagoon Nature Center and Nature trail. See this web site: http://www.sanelijo.org/naturecenter.html
There is a WONDERFUL petting zoo at San Juan Capistrano. Maybe one of the best in the country! See this web site: http://www.zoomars.com/# It is very close to the train station there and the San Juan Capistrano Mission (where the swallows return each year). A fun outing for children it to take the Amtrak or Metrolink train from Oceanside to San Juan Capistrano (about 15 minutes), walk to the petting zoo, have lunch, visit the mission, and come back home.
There are lots of very interesting walks, or hikes in the San Diego area. In particular there are a lot around the lagoons, but there are quite a few in the local hills and foothills. Priscilla Lister has a column in the San Diego Union Tribune each week that describes very interesting trails. Go to this search page: http://www.signonsandiego.com/search/?q=priscilla+lister to scan through her many columns.
One of the more interesting places is Queen Califia’s Magic Circle -- a free “sculpture garden” in Kit Carson Park in Escondido -- about 25 minutes from Oceanside. The unique area was designed by sculptress Niki De Saint Phalle, and was a huge artistic and engineering project. Our grand children have always enjoyed a visit there. See this web site: http://queencalifia.org/ The sculpure is so “far out” that kids love it--and they get to run around in some of it. There is also an arboretum. Our grandchildren enjoy playing in the stream nearby and exploring the fairly large park -- so I would call it a “nature” attraction.
Mission San Luis Rey is only a few miles from North Coast Village. In fact,there is a bike path that starts across the street from the complex and goes along the river to right near the mission. It is called the “king of the missions” and is an active church. There is a small fee-donation to tour the historical area, and children can see how they farmed during the era of the missions.
Oceanside has five shopping centers along California State Route 78, between Interstate 5 and El Camino Real.
There are several restaurants in the harbor area including Rockin' Baja Lobster, Fish-N-Chips, Crabby Bob's, Monterey Cannery, and the Jolly Roger.
The most dangerous place in Oceanside is the northern parts, near Camp Pendleton. This is where a officer was recently murdered. Libby Lake Park also has a negative reputation, as groups of teenagers have been targeted by gang members. Do not wander around at night with gang colors, and expect suspicious looking people at night.